Compositions with ph responsive copolymer containing maep and/or mahp and methods for using same

ABSTRACT

Disclosed is a pH responsive polymer made with mono-[2-(methacryloyloxy)ethyl]phthalate and/or mono-[2-(methacryloyloxy)ethyl hexahydro]phthalate. Also disclosed is an aqueous coating composition including at least one latex polymer derived from at least one monomer copolymerized or blended with alkali swellable acrylate copolymer. Also provided is an aqueous coating composition including at least one latex polymer derived from at least one monomer blended with alkali swellable acrylate copolymer, at least one pigment, and water. Also provided is a method of preparing an aqueous coating composition such as a latex paint including the above components. Also provided are methods of preparing mono-[2-(methacryloyloxy)ethyl]phthalate. Also provided are compositions and methods using the polymer in hydraulic fracturing, personal care and or home and industrial cleaners.

CROSS-REFERENCE TO RELATED APPLICATION

This claims the benefit of U.S. provisional patent application No.61/740,837, filed 21 Dec. 2012, incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to compositions and methods using a HASEcopolymer or ASE copolymer as a thickener for making paints andcoatings. In particular one of the monomers from which the HASE and/orASE copolymer is made is mono-[2-(methacryloyloxy)ethyl]phthalate (MAEP)(also known as 2-(2-carboxybenzoyloxy)ethyl methacrylate) and/ormono-[2-(methacryloyloxy)ethyl hexahydro]phthalate (MAHP) (also known asMonoacryloyloxyethy Hexahydrophthalate).

BACKGROUND OF THE INVENTION

Rheological additives are chemical compositions, which, added even insmall amounts, modify a liquid system's rheological properties, such asviscosity and response to shear. Such additives or thickeners may beused in a variety of liquid systems including aqueous systems such aspaints, aqueous inks, and personal care products and compositions fortreating subterranean formations. The additives improve the rheologicalproperties by also affecting the dispersion, suspension andemulsification of pigments, binders and other solids within a vehicle.

Thixotropic promoters are a category of rheology additives widely usedin the coating industry. They can be categorized as organic clay,polyethylene waxes and titanium derivatives. These thixotropic promotershave been used for a long time in latex paints and other architecturalcoatings. Many types of thixotropic promoters are used because each ofthem has its own limitations. Some, such as the organic clay, are veryeffective but they have disadvantages such as decreasing the gloss ofthe paint significantly. Thixotropic promoters are also used inhydraulic fracturing of subterranean formations, such as oil and naturalgas wells, and other methods of secondary oil recovery.

Hydrophobically modified alkali swellable emulsion (HASE, also known asHydrophobically modified alkali soluble) polymer systems and alkalisoluble emulsion (ASE) polymer systems are commonly employed to modifythe rheological properties of aqueous emulsion systems. These polymersare substantially insoluble in water at a low pH. However, at higher pHthey become swellable or soluble in water and thus exhibit thickeningbehavior. Under the influence of a base, organic or inorganic, the HASEparticles gradually swell and expand to form a three-dimensional networkby intermolecular hydrophobic aggregation between HASE copolymer chainsand/or with components of the emulsion. This network, combined with thehydrodynamic exclusion volume created by the expanded HASE chains,produces a thickening effect. This network is sensitive to appliedstress so it breaks down under shear and recovers when the stress isrelieved. Such rheological properties are particularly desirable forpaints and coatings because they make the formulation easy to apply ontoa surface while providing the thickness needed for uniform coverage andavoid spattering.

These alkali-swellable and alkali-soluble polymers are carboxylfunctional polymers synthesized by free radical polymerization. HASEcopolymer systems can be prepared from the following monomers: (a) anethylenically unsaturated carboxylic acid, (b) a nonionic ethylenicallyunsaturated monomer, and (c) an ethylenically unsaturated hydrophobicmonomer. Representative HASE copolymer systems include those shown in EP226097 B1, EP 705852 B1, U.S. Pat. No. 4,384,096, U.S. Pat. No.5,874,495, U.S. Pat. No. 7,217,752 B2, and US patent applicationpublication 2006/0270563 A1, now U.S. Pat. Nos. 7,772,421 and 8,071,674,all incorporated herein by reference.

Three categories of polymers produced by emulsion polymerization are:(1) Synthetic rubber: some grades of styrene-butadiene (SBR), somegrades of polybutadiene, polychloroprene (Neoprene), nitrile rubber,acrylic rubber, fluoroelastomer (FKM); (2) Plastic: some grades of PVC,some grades of polystyrene, some grades of PMMA(polymethylmethacrylate), acrylonitrile-butadiene-styrene terpolymer(ABS), polyvinylidene fluoride, polytertrafluoroethylene (PTFE); and (3)Dispersions (i.e., polymers sold as aqueous dispersions).

Latex is an example of an emulsion polymer which is a water basedpolymer dispersion. Latex paints are used for a variety of applicationsincluding interior and exterior, and flat, semi-gloss and glossapplications. Latex is a stable dispersion (colloidal emulsion) ofrubber or plastic polymer microparticles in an aqueous medium. Latexesmay be natural or synthetic.

It would be desirable to have a as a thixotropic promoter that providesimproved viscosity control, sagging, and leveling, while maintaininggloss in latex paints and coatings.

Hydraulic fracturing of the subterranean formation is conducted toincrease oil and/or gas production. Fracturing is caused by injecting aviscous fracturing fluid or a foam at a high pressure (hereinafterinjection pressure) into the well to form a fracture. As the fracture isformed, the particulate material, referred to as a “propping agent” or“proppant” is placed in the formation to maintain the fracture in apropped condition when the injection pressure is released. Coated and/oruncoated particles are often used as proppants to keep open fracturesimposed by hydraulic fracturing upon a subterranean formation, e.g., anoil or gas bearing strata. Particles typically used to prop fracturesgenerally comprise sand or sintered ceramic particles as the fractureforms, the proppants are carried into the fracture by suspending them inadditional fluid or foam to fill the fracture with slurry of proppant inthe fluid or foam. Upon release of the pressure, the proppants form apack that serves to hold open the fractures. Thus, the proppantsincrease production of oil and/or gas by providing a conductive channelin the formation. There is a need for a proppant carrier that canprevent settling of proppants or sand being positioned in the fractures.

During primary recovery a subterranean formation produces the oil bypressure depletion. In pressure depletion, the pressure differencebetween the formation and a production well or wells forces the oilcontained within the formation toward a production well where it can berecovered. Typically, up to 35 percent of the oil initially contained ina formation can be recovered using pressure depletion. Methods have beendeveloped to recover oil which could not be recovered using onlypressure depletion techniques or secondary recovery techniques. Thesemethods are typically referred to as “enhanced oil recovery techniques”(EOR).

One enhanced oil recovery process is referred to as surfactant flooding.This generally covers the use of an aqueous fluid containing surfactantinjected into an oil rich formation to displace oil from the formationand the displaced oil is then recovered.

Another enhanced oil recovery process is referred to as chemicalflooding. This generally covers the use of polymer and/or surfactantslugs. In polymer flooding, a polymer solution is injected to displaceoil toward producing wells. The polymer solution is designed to developa favorable mobility ratio between the injected polymer solution and theoil/water bank being displaced ahead of the polymer. In surfactantflooding, an aqueous solution containing surfactant is injected into theoil rich formation. Residual oil drops are deformed as a result of lowinterfacial tension provided by surfactant solution and drops aredisplaced through the pore throats and displaced oil is then recovered.

U.S. Pat. No. 4,432,881, incorporated herein by reference in itsentirety, discloses an aqueous liquid medium having increased low shearviscosity as provided by dispersing into the aqueous medium (1) awater-soluble polymer having pendant hydrophobic groups, e.g., anacrylamide dodecyl acrylate copolymer, and (2) a water-dispersiblesurfactant, e.g., sodium oleate, or dodecyl polyethyleneoxy glycolmonoether.

U.S. Pat. No. 4,541,935, incorporated herein by reference in itsentirety, discloses fracturing processes which use aqueous hydraulicfracturing fluids. The fluids comprise: (a) an aqueous medium, and (b) athickening amount of a thickener composition comprising (i) awater-soluble or water-dispersible interpolymer having pendanthydrophobic groups chemically bonded thereto, (ii) a nonionic surfactanthaving a hydrophobic group(s) capable of associating with thehydrophobic groups on said organic polymer, and (iii) a water-solubleelectrolyte.

U.S. Pat. No. 5,566,760, incorporated herein by reference in itsentirety, discloses a fracturing fluid comprising surfactants andhydrophobically-modified polymers.

U.S. Pat. No. 7,084,095, incorporated herein by reference in itsentirety, discloses addition of polymers to a viscoelastic surfactantbase system allows adjusting the rheological properties of the basefluid.

U.S. Pat. No. 7,427,583, incorporated herein by reference in itsentirety, describes an aqueous viscoelastic fracturing fluid for use inthe recovery of hydrocarbons. The fluid comprises a viscoelasticsurfactant and a hydrophobically modified polymer.

U.S. Pat. No. 7,727,937 to Pauls et al, incorporated herein by referencein its entirety, discloses acidic treatment fluids used in industrialand/or subterranean operations, and more particularly, acidic treatmentfluids comprising clarified xanthan gelling agents, and methods of usein industrial and/or subterranean operations.

U.S. Pat. No. 7,772,421 to Yang et al, incorporated herein by referencein its entirety, discloses a hydraulic fracturing composition comprisingwater, a pH responsive polymer and a proppant.

U.S. Pat. No. 7,789,160 to Hough et al, incorporated herein by referencein its entirety discloses an aqueous fluid useful for the recovery ofcrude oil from a subterranean formation, which includes a compositionincluding a mixture of water, a water soluble block copolymer, aninorganic salt and at least one member of the group of a nonionicsurfactant having an HLB of less than 12, and methods for using same.

U.S. Pat. No. 7,857,055 to Li et al, incorporated herein by reference inits entirety, discloses a fluid for treating a subterranean formationcomprising an aqueous solution of a polysaccharide, a polyacrylamide, acrosslinking agent, and less than 0.1% by weight of any clay component,wherein the polyacrylamide is present in an amount of from about 0.01percent to about 1 percent by weight of the fluid.

It would be desirable to provide stable fracturing fluids and EOR fluidsfor subterranean formations, such as natural gas and/or oil field.

Also, there is a need to enhance viscosity to improve personal carecompositions. In personal care applications, consumers are increasinglydemanding formulations that provide multiple benefits such as, but notlimited to, unique sensory experience, enhanced moisturization,increased conditioning, improved delivery of active ingredients andcompatibility. Synthetic rheology modifier polymers can be employed toassist in achieving one or more of these properties.

Also there is a need to enhance viscosity to improve cleaningcompositions for home and industry.

SUMMARY OF THE INVENTION

The invention is directed to pH responsive copolymer of a mixture ofunsaturated copolymerizable monomers, the unsaturated copolymerizablemonomers comprising, based on total weight of monomers:

A. about 0.1-70 weight percent, typically 0.5-50, 0.7-40, 1-40, 5-40,5-30 or 10 to 40 weight percent of at least one alpha beta-ethylenicallyunsaturated first acid monomer selected from the group consisting ofmono-[2-(methacryloyloxy)ethyl]phthalate (also known as2-(2-carboxybenzoyloxy)ethyl methacrylate, MAEP) andmono-[2-(Methacryloyloxy)ethyl hexahydro]phthalate (MAHP),

B. about 0-45 weight percent, preferably 5 to 30 weight percent, of atleast one C3-C8 alpha beta-ethylenically unsaturated acidic monomer,preferably a C3-C8 alpha beta-ethylenically unsaturated carboxylic acidmonomer;

C. about 15-70 weight percent, typically 20 to 50 weight percent, of atleast one non-ionic, copolymerizable C2-C12 alpha, beta-ethylenicallyunsaturated monomer; and

D. about 0 to 30 weight percent, preferably 0.05 to 30 weight percent ortypically 5 to 20 weight percent, of at least one non-ionicethylenically unsaturated hydrophobic monomer.

The pH responsive copolymer is also known as a HASE or ASE copolymer.The HASE copolymer includes component D and the ASE copolymer does notinclude component D.

The present invention also includes compositions such as aqueousdispersions comprising this pH responsive copolymer. In particular theinvention is also directed using the pH responsive copolymer as anadditive for latex binders, paints and aqueous coatings. This pHresponsive copolymer additive is a thickener used as a thixotropicpromoter during formulation of the latex binders, paints and aqueouscoatings, compositions for treating subterranean formations, home careand personal care.

The invention is also directed to a homogeneous, pourable liquid whichimproves sagging properties in coatings without a significant decreasein gloss. The improved sagging property is due to the thixotropicbehavior of the HASE and/or ASE copolymer thickener synthesized with theabove mentioned monomer. In addition the new thixotropic promoter onlyneeds low shear for incorporation.

The aqueous coating compositions of the invention typically include atleast one latex polymer derived from at least one monomer, for exampleacrylic monomers. The at least one latex polymer in the aqueous coatingcomposition can be a pure acrylic, a styrene acrylic, a vinyl acrylic oran acrylated ethylene vinyl acetate copolymer and is more preferably apure acrylic. The at least one latex polymer is preferably derived fromat least one acrylic monomer selected from the group consisting ofacrylic acid, acrylic acid esters, methacrylic acid, and methacrylicacid esters. For example, the at least one latex polymer can be a butylacrylate/methyl methacrylate copolymer or a 2-ethylhexyl acrylate/methylmethacrylate copolymer. Typically, the at least one latex polymer isfurther derived from one or more monomers selected from the groupconsisting of styrene, alpha-methyl styrene, vinyl chloride,acrylonitrile, methacrylonitrile, ureido methacrylate, vinyl acetate,vinyl esters of branched tertiary monocarboxylic acids, itaconic acid,crotonic acid, maleic acid, fumaric acid, ethylene, and C4-C8 conjugateddienes.

Latex paint formulations typically comprise additives, e.g., at leastone pigment. In a preferred embodiment of the invention the latex paintformulation includes at least one pigment selected from the groupconsisting of TiO2, CaCO3, clay, aluminum oxide, silicon dioxide,magnesium oxide, sodium oxide, potassium oxide, talc, barytes, zincoxide, zinc sulfite and mixtures thereof. More preferably the at leastone pigment includes TiO2, calcium carbonate or clay.

In addition to the above components, the aqueous coating composition caninclude one or more additives selected from the group consisting ofdispersants, surfactants, rheology modifiers, defoamers, thickeners,biocides, mildewcides, colorants, waxes, perfumes and co-solvents.

The present invention is also directed to new processes for makingmono-[2-(methacryloyloxy)ethyl]phthalate (also known as2-(2-carboxybenzoyloxy)ethyl methacrylate, MAEP).

Compositions of the present invention may have an absence of one or moreof anionic surfactant, cationic surfactant, nonionic surfactant,zwitterionic surfactant, and/or amphoteric surfactant.

These and other features and advantages of the present invention willbecome more readily apparent to those skilled in the art uponconsideration of the following detailed description, which describe boththe preferred and alternative embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows Viscosity Profiles of formulations prepared with HASEthickeners containing MAEP and MAHP (in RHOPLEX SG30).

FIG. 2 shows Yield Stress of formulations prepared with HASE thickenerscontaining MAEP and MAHP (in RHOPLEX SG30).

FIG. 3 shows thixotropic measurement of Binder and HASE Polymer System Kof HASE polymer 12 in RHOPLEX SG30 (couette).

FIG. 4 shows the measurement of Binder and HASE Polymer System J of HASEpolymer 11 in RHOPLEX SG30 (couette).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to the use of a particular family of HASEand/or ASE copolymers for latex dispersions, binders, paints andcoatings. The present invention provides aqueous compositions, forexample, aqueous coating compositions. The aqueous compositions of theinvention are aqueous polymer dispersions which include at least onelatex polymer. Paints or other aqueous coatings of the present inventiontypically further include at least one pigment. Typically the latex hasa Tg of less than 10° C., more typically less than 5° C., still moretypically in the range from 5 to −10° C., e.g., 0° C.

As used herein, the term “alkyl” means a monovalent straight or branchedsaturated hydrocarbon radical, more typically, a monovalent straight orbranched saturated (C₁-C₄₀) hydrocarbon radical, such as, for example,methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl,hexyl, octyl, hexadecyl, octadecyl, eicosyl, behenyl, tricontyl, andtetracontyl.

As used herein, the term “alkenyl” means an unsaturated straight orbranched hydrocarbon radical, more typically an unsaturated straight,branched, (C₂-C₂₂) hydrocarbon radical, that contains one or morecarbon-carbon double bonds, such as, for example, ethenyl, n-propenyl,iso-propenyl.

As used herein, the term “alkoxyl” means an oxy radical that issubstituted with an alkyl group, such as for example, methoxyl, ethoxyl,propoxyl, isopropoxyl, or butoxyl, which may optionally be furthersubstituted on one or more of the carbon atoms of the radical.

As used herein, the term “alkoxyalkyl” means an alkyl radical that issubstituted with one or more alkoxy substituents, more typically a(C₁-C₂₂)alkyloxy-(C₁-C₆)alkyl radical, such as methoxymethyl, andethoxybutyl.

As used herein, terms “aqueous medium” and “aqueous media” are usedherein to refer to any liquid medium of which water is a majorcomponent. Thus, the term includes water per se as well as aqueoussolutions and dispersions.

As used herein, the term “aryl” means a monovalent unsaturatedhydrocarbon radical containing one or more six-membered carbon rings inwhich the unsaturation may be represented by three conjugated doublebonds, which may be substituted one or more of carbons of the ring withhydroxy, alkyl, alkoxyl, alkenyl, halo, haloalkyl, monocyclic aryl, oramino, such as, for example, phenyl, methylphenyl, methoxyphenyl,dimethylphenyl, trimethylphenyl, chlorophenyl, trichloromethylphenyl,triisobutyl phenyl, tristyrylphenyl, and aminophenyl.

As used herein, the term “arylalkyl” means an alkyl group substitutedwith one or more aryl groups, more typically a (C₁-C₁₈)alkyl substitutedwith one or more (C₆-C₁₄)aryl substituents, such as, for example,phenylmethyl, phenylethyl, and triphenylmethyl.

As used herein, the term “aryloxy” means an oxy radical substituted withan aryl group, such as for example, phenyloxy, methylphenyl oxy,isopropylmethylphenyloxy.

The “bicyclo[d.e.f]” notation is used herein in reference tobicycloheptyl and bicycloheptenyl ring systems in accordance with thevon Baeyer system for naming polycyclic compounds, wherein a bicyclicsystem is named by the prefix “bicyclo-” to indicate number of rings inthe system, followed by a series of three arabic numbers, listed indescending numerical order, separated by full stops, and enclosed insquare brackets, to indicate the respective number of skeletal atoms ineach acyclic chain connecting the two common atoms (the “bridgeheadatoms”), excluding the bridgehead atoms.

A bridgehead atom is any skeletal atom of the ring system bonded tothree or more skeletal atoms (excluding hydrogen). A bicyclic system(which comprises the main ring and main bridge only) is named by: theprefix bicyclo- (indicating the number of rings); numbers indicating thebridge lengths (i.e. number of skeletal atoms excluding the bridgeheadatoms) separated by full stops and placed in square brackets. The threenumbers are cited in decreasing order of size (e.g.[3.2.1]); the name ofthe hydrocarbon indicating the total number of skeletal atoms. Forexample, bicyclo[3.2.1]octane is the name for the structure of FormulaI.

As used herein, the terminology “(C_(x)-C_(y))” in reference to anorganic group, wherein x and y are each integers, indicates that thegroup may contain from x carbon atoms to y carbon atoms per group.

As used herein, the term “cycloalkenyl” means an unsaturated hydrocarbonradical, typically an unsaturated (C₅-C₂₂) hydrocarbon radical, thatcontains one or more cyclic alkenyl rings and which may optionally besubstituted on one or more carbon atoms of the ring with one or two(C₁-C₆)alkyl groups per carbon atom, such as cyclohexenyl,cycloheptenyl, and “bicycloalkenyl” means a cycloalkenyl ring systemthat comprises two condensed rings, such as bicycloheptenyl.

As used herein, the term “cycloalkyl” means a saturated hydrocarbonradical, more typically a saturated (C₅-C₂₂) hydrocarbon radical, thatincludes one or more cyclic alkyl rings, which may optionally besubstituted on one or more carbon atoms of the ring with one or two(C₁-C₆)alkyl groups per carbon atom, such as, for example, cyclopentyl,cycloheptyl, cyclooctyl, and “bicyloalkyl” means a cycloalkyl ringsystem that comprises two condensed rings, such as bicycloheptyl.

As used herein, an indication that a composition is “free” of a specificmaterial means the composition contains no measurable amount of thatmaterial.

As used herein, the term “heterocyclic” means a saturated or unsaturatedorganic radical that comprises a ring or condensed ring system,typically comprising from 4 to 16 ring atoms per ring or ring system,wherein such ring atoms comprise carbon atoms and at least oneheteroatom, such as for example, O, N, S, or P per ring or ring system,which may optionally be substituted on one or more of the ring atoms,such as, for example, thiophenyl, benzothiphenyl, thianthrenyl, pyranyl,benzofuranyl, xanthenyl, pyrolidinyl, pyrrolyl, pyradinyl, pyrazinyl,pyrimadinyl, pyridazinyl, indolyl, quinonyl, carbazolyl, phenathrolinyl,thiazolyl, oxazolyl, phenoxazinyl, or phosphabenzenyl.

As used herein, the term “hydroxyalkyl” means an alkyl radical, moretypically a (C₁-C₂₂)alkyl radical, that is substituted with one or morehydroxyl groups, such as for example, hydroxymethyl, hydroxyethyl,hydroxypropyl, and hydroxydecyl.

As used herein the term “(meth)acrylate” refers collectively andalternatively to the acrylate and methacrylate and the term“(meth)acrylamide” refers collectively and alternatively to theacrylamide and methacrylamide, so that, for example, “butyl(meth)acrylate” means butyl acrylate and/or butyl methacrylate.

As used herein, “molecular weight” in reference to a polymer or anyportion thereof, means to the weight-average molecular weight (“M_(w)”)of the polymer or portion. M_(w) of a polymer is a value measured by gelpermeation chromatography (GPC) with an aqueous eluent or an organiceluent (for example dimethylacetamide, dimethylformamide, and the like),depending on the composition of the polymer, light scattering (DLS oralternatively MALLS), viscometry, or a number of other standardtechniques. M_(w) of a portion of a polymer is a value calculatedaccording to known techniques from the amounts of monomers, polymers,initiators and/or transfer agents used to make the portion.

In one embodiment, the copolymers for use in the present inventionexhibit a weight average molecular weight, as determined by gelpermeation chromatography (GPC) and light scattering of a solution ofthe polymer in tetrahydrofuran and compared to a polystyrene standard,of greater than or equal to 30,000 grams per mole (“g/mole”). HASEthickeners may not fully dissolve in THF but after hydrolysis they candissolve in water and measurement can be run in a water gel permeationchromatography (GPC). Reference: Macromolecules 2000, 33, 2480. Forexample in a range of 30,000 to 2,000,000 g/mole.

As used herein, the indication that a radical may be “optionallysubstituted” or “optionally further substituted” means, in general,unless further limited either explicitly or by the context of suchreference, such radical may be substituted with one or more inorganic ororganic substituent groups, for example, alkyl, alkenyl, aryl,arylalkyl, alkaryl, a hetero atom, or heterocyclyl, or with one or morefunctional groups capable of coordinating to metal ions, such ashydroxyl, carbonyl, carboxyl, amino, imino, amido, phosphonic acid,sulphonic acid, or arsenate, or inorganic and organic esters thereof,such as, for example, sulphate or phosphate, or salts thereof.

As used herein, “parts by weight” or “pbw” in reference to a namedcompound refers to the amount of the named compound, exclusive, forexample, of any associated solvent. In some instances, the trade name ofthe commercial source of the compound is also given, typically inparentheses. For example, a reference to “10 pbw cocoamidopropylbetaine(“CAPB”, as MIRATAINE BET C-30)” means 10 pbw of the actual betainecompound, added in the form of a commercially available aqueous solutionof the betaine compound having the trade name “MIRATAINE BET C-30”, andexclusive of the water contained in the aqueous solution.

As used herein, an indication that a composition is “substantially free”of a specific material, means the composition contains no more than aninsubstantial amount of that material, and an “insubstantial amount”means an amount that does not measurably affect the desired propertiesof the composition.

As used herein, the term “surfactant” means a compound that reducessurface tension when dissolved in water.

“Surfactant effective amount” means the amount of the surfactant thatprovides a surfactant effect to enhance the stability of emulsions ofthe polymers.

I. pH Responsive Copolymer

The invention is directed to a pH responsive copolymer of a mixture ofunsaturated copolymerizable monomers. These pH responsive copolymers aresubstantially insoluble in water at a low pH. However, at higher pH theybecome swellable or soluble in water and thus exhibit thickeningbehavior. Thus, the pH responsive copolymer is interchangeably termedalkali swellable copolymer or alkali soluble copolymer. Typically the pHresponsive copolymer is termed an alkali-soluble emulsion (ASE)copolymer and/or a hydrophobically modified alkali-soluble emulsion(HASE) copolymer. Although this copolymer is described as ASE and/orHASE copolymer it is not necessary to make a copolymer of this structureby emulsion polymerization. The copolymer may also be made by solutionpolymerization and comes within the invention whether made by emulsionpolymerization or solution polymerization.

The pH responsive copolymer is made from a mixture of unsaturatedcopolymerizable monomers, the unsaturated copolymerizable monomerscomprising, based on total weight of monomers:

A. about 0.1-70 weight percent, typically 0.5-50, 0.7-40, 1-40, 5-40,5-30 or 10 to 40 weight percent, of at least one alphabeta-ethylenically unsaturated first acid monomer selected from thegroup consisting of mono-[2-(methacryloyloxy)ethyl]phthalate (MAEP)(also known as 2-(2-carboxybenzoyloxy)ethyl methacrylate, MAEP) havingthe structure A.I:

CAS No. 27697-00-3; Chemical FormulaC14H14O6, molecular weight 278.08;and

mono-[2-(methacryloyloxy)ethyl hexahydro]phthalate (MAHP) (also known asMonoacryloyloxyethy Hexahydrophthalate) having the structure A.II

CAS No. 51252-88-1, molecular formula 014H20O6, molecular weight 284.31.

B. about 0-45 weight percent, preferably 5 to 30 weight percent, of atleast one C3-C8 alpha, beta-ethylenically unsaturated first acidicmonomer, preferably a C3-C8 alpha beta-ethylenically unsaturatedcarboxylic acid monomer;

C. about 15-70 weight percent, typically 20 to 50 weight percent, of atleast one nonionic monomer, each comprising a nonionic substituentgroup, copolymerizable C2-C12 alpha, beta-ethylenically unsaturatedmonomer; and

D. about 0 to 30 weight percent, preferably 0.05 to 30 weight percent ortypically 5 to 20 weight percent, of at least one non-ionicethylenically unsaturated hydrophobic monomer.

In terms of monomeric units of the resulting pH responsive copolymer,rather than monomers from which the pH responsive copolymer is made, thepH responsive copolymer comprises:

A. about 0.1-70 weight percent, typically 0.5-50, 0.7-40, 1-40, 5-40,5-30 or 10 to 40 weight percent first acidic monomeric units derived byopening the alpha beta-ethylenic unsaturated bond of at least one memberof the group consisting of mono-[2-(methacryloyloxy)ethyl]phthalate(also known as 2-(2-carboxybenzoyloxy)ethyl methacrylate, MAEP)mono-[2-(Methacryloyloxy)ethyl hexahydro]phthalate (MAHP);

B. about 0-45 weight percent, preferably 5 to 30 weight percent, secondacidic monomeric units, preferably each second acidic monomeric unitindependently comprises a carboxylic acid-functional substituent group;

C. about 15-70 weight percent, typically 20 to 50 weight percent,nonionic monomeric units, each comprising a nonionic substituent group.The non-ionic monomeric units, each independently comprising a nonionicsubstituent group, for example Ethyl Acrylate (EA) monomer; and

D. about 0 to 30 weight percent, preferably 0.05 to 30 weight percent ortypically 5 to 20 weight percent, of at least one non-ionicethylenically unsaturated hydrophobic monomeric unit.

The ASE copolymer lacks the non-ionic ethylenically unsaturatedhydrophobic monomeric units. In contrast, the HASE copolymer includesthe hydrophobic monomeric units in an amount of about 0.05-30 weightpercent hydrophobic monomer units based on total weight of monomers.

The first acidic monomeric units assist to prevent sagging.

The second acidic monomeric units provide solubility and sagging.Typical second acidic monomeric units each independently comprise atleast one acid group per monomeric unit, for example, a sulfonic acidgroup, a phosphonic acid group, a phosphoric acid group, or a carboxylicacid-functional substituent group. Typically the second acidic monomericunits, each independently comprise a carboxylic acid-functionalsubstituent group, for example, methacrylic acid (MAA).

The nonionic monomeric units, for example slightly insoluble ethylacrylate (EA) or butyl acrylate (BA), segments enhance the thickeningperformance by promoting hydrophobic aggregations.

The hydrophobic macro monomers are responsible for intra-/intermolecularassociations. For example, they are specialty monomers which typicallyinclude a polymerizable group, a hydrophobic macro group and a bivalentpolyether group of a poly (ethylene oxide) chain, usually 5-100 ethyleneoxide units (typically 6-10 EO groups) and optionally 0-5 propyleneoxide units to favor the intermolecular aggregation. The bivalentpolyether group typically links the hydrophobic macro groups to thepolymerizable group. The polymerizable group typically becomes part ofthe backbone of the pH responsive copolymer and the bivalent polyethergroup linking group and macro group becomes a side chain of the pHresponsive copolymer. Examples of this side chain comprising thebivalent polyether group linking group and macro group are abicycloheptyl-polyether group, a bicycloheptenyl-polyether group or abranched (C₅-C₅₀)alkyl-polyether group, wherein thebicycloheptyl-polyether or bicycloheptenyl-polyether group mayoptionally be substituted on one or more ring carbon atoms by one or two(C₁-C6)alkyl groups per carbon atom.

Formula III shows an idealized diagram of the structure of an embodimentof this HASE copolymer made from alpha beta-ethylenic unsaturated bondof mono-[2-(methacryloyloxy)ethyl]phthalate (also known as2-(2-carboxybenzoyloxy)ethyl methacrylate, MAEP) as the first acidicmonomer, methacrylic acid as the second acidic monomer, ethyl acrylateas the nonionic monomer and a hydrophobic polymer. The hydrophobicpolymer having a polyethylene oxide chain as a bivalent polyether grouplinking a polymerizable functional group and a C18H37 macro hydrophobicgroup.

Formula IV shows an idealized diagram of the structure of an ASEcopolymer made from alpha beta-ethylenic unsaturated bond ofmono-[2-(methacryloyloxy)ethyl]phthalate (also known as2-(2-carboxybenzoyloxy)ethyl methacrylate, MAEP) as the first acidicmonomer, methacrylic acid as the second acidic monomer, ethyl acrylateas the nonionic monomer, and a hydrophobic polymer having apolymerizable functional group, a C18H37 macro hydrophobic group and anethylene oxide chain as a bivalent polyether group linking thepolymerizable functional group and a C18H37 macro hydrophobic group.

Formula V shows an idealized diagram of the structure of this HASEcopolymer made from alpha beta-ethylenic unsaturated bond ofmono-[2-(Methacryloyloxy)ethyl hexahydro]phthalate (MAHP) as the firstacidic monomer, methacrylic acid as the second acidic monomer, ethylacrylate as the nonionic monomer, and a hydrophobic polymer having apolymerizable functional group, a C18H37 macro hydrophobic group and anethylene oxide chain as a bivalent polyether group linking thepolymerizable functional group and a C18H37 macro hydrophobic group.

Formula VI shows an idealized diagram of the structure of an ASEcopolymer made from mono-[2-(Methacryloyloxy)ethyl hexahydro]phthalate(MAHP) as the first acidic monomer, methacrylic acid as the secondacidic monomer, ethyl acrylate as the nonionic monomer, and ahydrophobic polymer having a polymerizable functional group, a C18H37macro hydrophobic group and an ethylene oxide chain as a bivalentpolyether group linking the polymerizable functional group and a C18H37macro hydrophobic group.

The ASE and/or HASE copolymer comprises a chain of monomeric units. Thepolymer is a macromolecule having a relatively high molecular mass thatcomprises chains of multiple repetitions of the monomeric units, whichare derived, actually or conceptually, from molecules of relatively lowmolecular mass and are connected to form a linear, branched, or networkstructure. The copolymer typically has a linear or branched structure,more typically single strand linear or branched structure. In oneembodiment, a polymer having a predominantly single strand linear orbranched structure is lightly crosslinked to form a polymer networkhaving a low density of crosslinks. As used herein the term “singlestrand” in regard to a polymer means monomeric units of the polymer areconnected such that adjacent monomeric units are joined to each otherthrough two atoms, one on each of the adjacent monomeric units.

The copolymer may typically be regarded as having a “backbone”, or mainpolymer chain, from which all branches and substituent groups of thepolymer may be regarded as being pendant. Where two or more chains ofthe copolymer could equally be considered to be the main chain of thepolymer, that chain is selected as the main chain which leads to thesimplest representation of the polymer molecule. The monomeric units ofthe copolymer may be arranged in random, alternating, tapered, or blocksequence along the copolymer chain.

The ASE and/or HASE copolymer typically has a weight average molecularweight of greater than or equal to about 30,000 grams per mole,typically the copolymer has a weight average molecular weight of greaterthan or equal to about 30,000 to 1,000,000 grams per mole or 30,000 to500,000 grams per mole or 50,000 to 500,000 grams per mole.

A. First Acidic Monomers for pH Responsive Copolymer

The alpha beta-ethylenically unsaturated first acid monomer is selectedfrom the group consisting of mono-[2-(methacryloyloxy)ethyl]phthalate(also known as 2-(2-carboxybenzoyloxy)ethyl methacrylate, MAEP) andmono-[2-(Methacryloyloxy)ethyl hexahydro]phthalate (MAHP).

Mono-[2-(Methacryloyloxy)ethyl hexahydro]phthalate (MAHP) has thestructure A.II:

It is commercially available from Wako Pure Chemical Industries.

It has the CAS No. 51252-88-1, the molecular formula C14H20O6, and amolecular weight of 284.31 g/mol.

Mono-[2-(methacryloyloxy)ethyl]phthalate has the structure A.I:

MAEP has the chemical formula 014H14O6 and a molecular weight of 278.08g/mol.

There are a number of routes to makingmono-[2-(methacryloyloxy)ethyl]phthalate. For example it can be made bymethod AA:

MEHQ is mono methyl ether of hydroquinone (also known as 4-methoxyphenol). It is an inhibitor to prevent Hydroxyethylmethacrylate (HEMA)and HEMA Phthalate monomer from self reacting.

There are various methods to makemono-[2-(methacryloyloxy)ethyl]phthalate while using a catalyst to lowerreaction temperatures. For example, U.S. Pat. No. 3,689,427 (Aug. 27,1969) discloses synthesis using catalytic N,N-dimethylbenzylamine and nosolvent. JP48089947 (1973) discloses synthesis using catalytictriethylamine and no solvent. CN10110880 (Jun. 21, 2007) disclosessynthesis using organic solvent and several catalysts includingpyridine, ethylenediamine and triethylenediamine. Sedlakova et al.,Synthesis of 2-(2-carboxybenzoyloxy)ethyl methacrylate and its radicalpolymerizatin and copolymerization with butyl methacrylate, DieAngewandte Makromolekulare Chemie, 201, 33-48 (1992) discloses synthesisusing organic solvent, and several catalysts including pyridine,triethylamine and p-toluenesulfonic acid. All of these patents, patentapplications and non-patent literature are incorporated herein byreference.

1. Processes Using Imidazole

A novel process of the present invention for makingmono-[2-(methacryloyloxy)ethyl]phthalate employs imidazole to serve as anucleophile catalyst to activate phthalic anhydride and then as aleaving group on acylated intermediate. This process employing imidazolealso employs MEHQ as an inhibitor to prevent HEMA from self reacting.

The use of imidazole in activation of anhydrides within analyticalprocedures is documented by Evtushenko et al, Chemistry of HeterocyclicCompounds 2000, 36, 1054 and Carey et al, Journal of Cellular Plastics1984, Jan.-Feb. This reference describes imidazole as a useful catalystin activating anhydrides. However, this reference does not reveal theuse of imidazole to synthesize mono-[2-(methacryloyloxy)ethyl]phthalate.

This process comprises the steps of:

mixing 100 parts by weight 2-hydroxyethy methacrylate (HEMA) and 0.1 to0.5 parts by weight 4-methoxyphenol (MEHQ) to form a mixture;

heating the mixture to a set point of 70-100° C. and then adding 25-50parts by weight phthalic anhydride as a first dose of phthalic anhydrideto the heated mixture;

after adding the first dose of phthalic anhydride then adding 1-3 partsby weight imidazole to the mixture during which an exotherm was noted;

after adding the imidazole then adding 50 to 90 parts by weight phthalicanhydride as a second dose of phthalic anhydride;

after adding the second dose of phthalic anhydride then heating thereaction mixture at 70-90° C. for several hours to formmono-[2-(methacryloyloxy)ethyl]phthalate; and

recovering the mono-[2-(methacryloyloxy)ethyl]phthalate.

The reaction mixture was sparged with 8% oxygen in nitrogen throughoutthe process However, the reaction also works without NOx (92/2 N₂/O₂).

2. Process Using 2,6-Di-Tert-Butyl-4-(Dimethylaminomethyl) Phenol or2,4,6-Tris(Dimethylaminomethyl)Phenol with an Absence of MEHQ and anAbsence of Base Catalyst

Another preferred novel process of the present invention for makingmono-[2-(methacryloyloxy)ethyl]phthalate uses2,6-di-tert-butyl-4-(dimethylaminomethyl)phenol or2,4,6-tris(dimethylaminomethyl)phenol without MEHQ or base catalyst. Inthis role they serve as both catalyst and inhibitor.

This process comprises using2,6-di-tert-butyl-4-(dimethylaminomethyl)phenol or2,4,6-tris(dimethylaminomethyl)phenol as a catalyst to activate phthalicanhydride and as an inhibitor to prevent HEMA from self-reacting in theabsence of additional catalyst. Thus, in this process there is anabsence of MEHQ and an absence of base catalyst. The2,6-di-tert-butyl-4-(dimethylaminomethyl)phenol or2,4,6-tris(dimethylaminomethyl)phenol each have dual functionality inthis process. In particular they each act as a catalyst for the desiredreaction of phthalic anhydride and HEMA and an inhibitor to prevent HEMAfrom self reacting. As sterically hindered phenols, both have therecognized ability to serve as radical inhibitors, inhibiting HEMA fromself-reacting.

2,6-di-tert-butyl-4-(dimethylaminomethyl)phenol has formula A.III:

2,4,6-tris(dimethylaminomethyl)phenol has the following formula A.IV:

This process comprises the steps of:

mixing 15-25 parts by weight 2-hydroxyethy methacrylate (HEMA) and atleast one member of the group consisting of 1-3 parts by weight2,6-di-tert-butyl-4-((dimethylamino)methyl)phenol or 0.2-2 parts byweight 2,4,6-tris((dimethylamino)methyl)phenol;

heating the mixture to a set point of 70-100° C. and then adding 10-30parts by weight phthalic anhydride to the heated mixture;

after adding the phthalic anhydride then heating the reaction mixture at70-90° C. for several hours to formmono-[2-(methacryloyloxy)ethyl]phthalate; and

recovering the mono-[2-(methacryloyloxy)ethyl]phthalate.

The reaction mixture was sparged with 8% oxygen in nitrogen (NOx)throughout the process.

3. Process Using 2,6-Di-Tert-Butyl-4-(Dimethylaminomethyl) Phenol or2,4,6-Tris(Dimethylaminomethyl)Phenol with MEHQ in the Absence of BaseCatalyst

In another inventive process of the present invention, both2,6-di-tert-butyl-4-(dimethylaminomethyl)phenol or2,4,6-tris(dimethylaminomethyl)phenol could be used in the presence ofMEHQ and in an absence of organic base catalyst to make MAEP. In thisrole they serve as catalyst only.

This process for making mono-[2-(methacryloyloxy)ethyl]phthalatecomprises using 2,6-di-tert-butyl-4-(dimethylaminomethyl)phenol or2,4,6-tris(dimethylaminomethyl)phenol as a catalyst to activate phthalicanhydride with MEHQ but without organic base (catalyst) on commerciallyavailable reagents. In this process MEHQ is employed as a polymerizationinhibitor to prevent HEMA from self reacting.

The process comprises the steps of:

mixing 15-25 parts by weight 2-hydroxyethy methacrylate (HEMA) and atleast one member of the group consisting of 1-3 parts by weight2,6-di-tert-butyl-4-((dimethylamino)methyl)phenol or 0.2-2 parts byweight 2,4,6-tris((dimethylamino)methyl)phenol;

heating the mixture to a set point of 70-100° C. with NOx sparge andthen adding 10-30 parts by weight phthalic anhydride to the heatedmixture;

after adding the phthalic anhydride then heating the reaction mixture at70-90° C. to form mono-[2-(methacryloyloxy)ethyl]phthalate; and

recovering the mono-[2-(methacryloyloxy)ethyl]phthalate, wherein theprocess steps are performed in the absence of a base catalyst.

Thus, a) these two molecules2,6-di-tert-butyl-4-(dimethylaminomethyl)phenol or2,4,6-tris(dimethylaminomethyl)phenol have the following two functions:

1. polymerization inhibitor (due to phenyl ring and OH)

2. monomer reaction catalyst (due to amino groups) to make MAEP

b) Either 2,6-di-tert-butyl-4-(dimethylaminomethyl)phenol or2,4,6-tris(dimethylaminomethyl)phenol can be used to synthesize themonomer MAEP and no additional base catalyst is needed.

c) However, as explained below, monomer could be also synthesized byusing the 2,6-di-tert-butyl-4-(dimethylaminomethyl)phenol or2,4,6-tris(dimethylaminomethyl)phenol molecules and an additional basecatalyst.

4. Process Using 2,6-Di-Tert-Butyl-4-(Dimethylaminomethyl) Phenol or2,4,6-Tris(Dimethylaminomethyl)Phenol with Base Catalyst

In another alternative both2,6-di-tert-butyl-4-(dimethylaminomethyl)phenol or2,4,6-tris(dimethylaminomethyl)phenol could be used in the presence ofbase catalyst to make MAEP. In this role they serve as an inhibitor.Being an inhibitor is a known literature established role for thesereagents.

The base catalyst promotes the formation of product at a lowertemperature or in shorter time frame than in an uncatalyzed system. Whenadded to our system, lower reaction temp provided higher quality productthan uncatalyzed system. The base catalyst is a Lewis base catalyst. ALewis base is any species that donates a pair of electrons to a Lewisacid to form a Lewis adduct. For example, OH⁻ and NH₃ are Lewis bases,because they can donate a lone pair of electrons. Lewis base catalysisis the process by which an electron pair donor increases the rate of agiven chemical reaction by interacting with an acceptor atom in one ofthe reagents or substrates. The binding event may enhance either theelectrophilic or nucleophilic character of the bound species.Furthermore, the Lewis base should not be consumed or altered during thecourse of the reaction. A Lewis base is an atomic or molecular specieswhere the highest occupied molecular orbital is highly localized.Typical Lewis bases are amines such as ammonia and alkyl amines. Othercommon Lewis bases include pyridine and its derivatives. Some of themain classes of Lewis bases are amines of the formula NH_(3-x)R_(x)where R=alkyl or aryl, for example C1-C12 alkyl or C1-C12 aryl. Relatedto these are pyridine and its derivatives; phosphines of the formulaPR_(3-x)A_(x), where R=alkyl, A=aryl; and compounds of O, S, Se and Tein oxidation state 2, including water, ethers, ketones. The followingamines are typical base catalysts: triethylamine and imidazole.

This process for making mono-[2-(methacryloyloxy)ethyl]phthalatecomprises using 2,6-di-tert-butyl-4-(dimethylaminomethyl)phenol or2,4,6-tris(dimethylaminomethyl)phenol as a catalyst to activate phthalicanhydride with MEHQ (polymerization inhibitor) and organic base(catalyst) on commercially available reagents. In this process MEHQ isemployed as an inhibitor to prevent HEMA from self-reacting.

B. Second Acidic Monomeric Units for ASE or HASE Copolymer

The polymer of the present invention optionally further comprises secondacidic monomeric units, each independently comprising at least one acidgroup per second acidic monomeric unit.

In one embodiment, the second acidic monomeric units each independentlycomprise, per monomeric unit, at least one group according to structure(B.I):

—R³²-R³¹  (B.I)

whereinR³¹ is a moiety that comprises at least one carboxylic acid, sulfonicacid, or phosphoric acid group, andR³² is absent or is a bivalent linking group.

In one embodiment, R³² is O, —(CH₂)_(n)—O—, or is according to structure(structure (B.II):

wherein:n is an integer of from 1 to 6,

A is O or NR¹⁷, and

R¹⁷ is H or (C₁-C₄)alkyl.

In one embodiment, the second acidic monomeric units each independentlycomprise one or two carboxy groups per monomeric unit and may, if thesecond acidic monomeric unit comprises a single carboxy group, furthercomprise an ester group according to —CH₂COOR³³, wherein R³³ is alkyl,more typically, (C₁-C₆)alkyl.

The second acidic monomeric units may be made by known synthetictechniques, such as, for example, by grafting of one or more groupsaccording to structure (B.I) onto a polymer backbone, such as ahydrocarbon polymer backbone, a polyester polymer backbone, or apolysaccharide polymer backbone. In the alternative, they may be made bypolymerizing a monomer that comprises a reactive functional group and atleast one group according to structure (B.I) per molecule.

In one embodiment, the second acidic monomeric units are derived frompolymerizing a monomer comprising a reactive functional group and agroup according to structure (B.XXI) per molecule.

In one embodiment, the reactive functional group is an ethylenicallyunsaturated group so the monomer comprising a reactive functional groupis an ethylenically unsaturated monomer. As a result the second acidicmonomer comprises at least one site of ethylenic unsaturation, moretypically, an α-, β-unsaturated carbonyl moiety, and at least one groupaccording to structure (B.XXI) per molecule and is copolymerizable withthe first acidic monomer and the nonionic monomer and the hydrophobicmonomer.

In one embodiment the second acidic monomer comprises one or moreethylenically unsaturated monocarboxylic acid monomers according tostructure (B.III):

R³⁴-R³²-R³¹  (B.III)

wherein:

R³¹ and R³² are each as described above, andR³⁴ is a moiety having a site of ethylenic unsaturation.

In one embodiment, the compound according to structure (B.XXII) is anα-, β-unsaturated carbonyl compound. In one embodiment, R³⁴ is accordingto structure (B.IV):

wherein R¹⁹ is H or (C₁-C₄)alkyl.

Suitable second acidic monomers include, for example, ethylenicallyunsaturated carboxylic acid monomers, such as acrylic acid andmethacrylic acid, ethylenically unsaturated dicarboxylic acid monomers,such as maleic acid and fumaric acid, ethylenically unsaturated alkylmonoesters of dicarboxylic acid monomers, such as butyl methyl maleate,ethylenically unsaturated sulphonic acid monomers, such as vinylsulfonic acid 2-acrylamido-2-methylpropane sulfonic acid, and styrenesulfonic acid, and ethylenically unsaturated phosphonic acid monomers,such as vinyl phosphonic acid and allyl phosphonic acid, salts of anythereof, and mixtures of any thereof. Alternatively, correspondingethylenically unsaturated anhydride or acid chloride monomers, such asmaleic anhydride, may be used and subsequently hydrolyzed to give apendant moiety having two acid groups. The preferred second acidicmonomeric units are derived from one or more monomers selected fromacrylic acid, methacrylic acid, and mixtures thereof. Methacrylic acidhas the following formula B.V:

C. Nonionic Monomeric Units for ASE and/or HASE Copolymer

In one embodiment, the polymer of the present invention furthercomprises one or more nonionic monomeric units.

In one embodiment, the nonionic monomeric units each independentlycomprise, per monomeric unit, at least one group according to structure(C.I):

—R⁴²-R⁴¹  (C.I)

whereinR⁴¹ is alkyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl, aryl, arylalkyl, oraryloxy, andR⁴² is absent or is a bivalent linking group.

In one embodiment, R⁴¹ is (C₁-C₂₂)alkyl, (C₁-C₂₂)hydroxyalkyl,(C₂-C₂₂)alkoxyalkyl, (C₆-C₂₄)cycloalkyl, (C₆-C₄₀)aryl, or(C₇-C₄₀)arylalkyl, more typically (C₂-C₁₂)alkyl.

In one embodiment, R⁴¹ is (C₁-C₂₂)alkyl, more typically, (C₁-C₁₂)alkyl.

In one embodiment, R⁴² is O, —(CH₂)_(n)—O—, wherein n is an integer offrom 1 to 6, or is according to structure (C.II):

wherein:n is an integer of from 1 to 6,

A is O or NR¹⁷, and

R¹⁷ is H or (C₁-C₄)alkyl.

The nonionic monomeric units may be made by known synthetic techniques,such as, for example, by grafting of one or more groups according tostructure (C.XXIII) onto a polymer backbone, such as a hydrocarbonpolymer backbone, a polyester polymer backbone, or a polysaccharidepolymer backbone, or a backbone made by polymerization, with, forexample, the above described first acidic, second acidic, andhydrophobic monomers, of at least one other monomer selected frommonomers that comprise a reactive functional group and at least onegroup according to structure (C.XXIII) per molecule and copolymerizablewith the first, second, and third monomers. Alternatively, the nonionicmonomeric units may simply be non-grafted portions of a polymerbackbone.

In one embodiment, the nonionic monomeric units are derived from anonionic monomer, for example, ethyl acrylate, that comprises a reactivefunctional group and a group according to structure (C.XXIII), and iscopolymerizable with the first acidic monomers, second acidic monomersand hydrophobic monomers.

In one embodiment, the reactive functional group of the nonionic monomeris an ethylenically unsaturated group and the nonionic monomer is anethylenically unsaturated monomer comprising at least one site ofethylenic unsaturation, more typically, an α-, β-unsaturated carbonylmoiety and at least one group according to structure (C.XXIII) permolecule.

In one embodiment, the nonionic monomer comprises one or more compoundsaccording to structure (C.III):

R⁴³-R⁴²-R⁴¹  (C.III)

wherein:

R⁴¹ and R⁴² are each as described above, andR⁴³ is a moiety having a site of ethylenic unsaturation.

In one embodiment, the compound according to structure (C.III) is an α-,β-unsaturated carbonyl compound. In one embodiment, R⁴³ is according tostructure (C.IV):

wherein R¹⁹ is H or (C₁-C₄)alkyl.

Suitable nonionic monomers include unsaturated monomers containing atleast one group according to structure C.XXIII per molecule, including(meth)acrylic esters such as: methyl (meth)acrylate, ethyl(meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate,cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl(meth)acrylate, lauryl (meth)acrylate isobornyl (meth)acrylate, benzyl(meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl(meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate,phenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl(meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl(meth)acrylate, tert-butylaminoethyl (meth)acrylate, and acetoxyethyl(meth)acrylate, (meth)acrylamides such as, (meth)acrylamide, N-methylol(meth)acrylamide, N-butoxyethyl (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-isopropyl (meth)acrylamide, N-tert-butyl(meth)acrylamide, N-tert-octyl (meth)acrylamide, and diacetone(meth)acrylamide, vinyl esters such as vinyl acetate, vinyl propionate,vinyl 2-ethylhexanoate, N-vinylamides such as: N-vinylpyrrolidione,N-vinylcaprolactam, N-vinylformamide, and N-vinylacetamide, and vinylethers such as, methyl vinyl ether, ethyl vinyl ether, butyl vinylether, and hydroxybutyl vinyl ether, and ethylenically unsaturated arylcompounds, such as styrene.

In one embodiment, the HASE copolymer of the present invention iscrosslinked. A crosslinked polymer can be made by, for example, reactinga mixture of hydrophobic, first acidic, and second acidic monomers witha nonionic monomer having more than one reactive functional group, suchas for example, more than one site of ethylenic unsaturation permolecule. In one embodiment, the nonionic monomer comprises least onemonomeric compound having more than one (meth)acrylic group permolecule, such as, for example, allyl methacrylate, ethylene glycoldimethacrylate, butylene glycol dimethacrylate, diallyl pentaerythritol,methylenebisacrylamide, pentaerythritol di-, tri- and tetra-acrylates,divinyl benzene, polyethylene glycol diacrylates, bisphenol Adiacrylates, butanediol dimethacrylate, 2,2-dimethylpropanedioldimethacrylate, ethylene glycol dimethacrylate, phenylene diacrylate, ora mixture thereof.

Ethylene glycol dimethylacrylate has the following formula C.IV.

In one embodiment, the polymer of the present invention comprisesnonionic units derived from one or more (C₁-C₂₂)alkyl (meth)acrylicesters, more typically (C₁-C₁₂)alkyl (meth)acrylic esters, such as ethylacrylate, butyl methacrylate, or ethylhexyl acrylate.

D. Hydrophobic Monomers for HASE Copolymer

In contrast to the ASE copolymers, the HASE copolymers further comprisehydrophobic monomeric units derived from a hydrophobic monomer. Thesehydrophobic monomers are ethylenically unsaturated hydrophobic monomers.

Preferably, the hydrophobic monomeric units each independently comprise,per monomeric unit, at least one branched (C₅-C₅₀)alkyl orbicycloheptyl-polyether or bicycloheptenyl-polyether group according tostructure (D.I):

—R¹⁴-R¹³-R¹²-R¹¹  (D.I).

In one embodiment, R¹¹ is bicyclo[d.e.f]heptyl orbicyclo[d.e.f]heptenyl, wherein d is 2, 3, or 4, e is 1 or 2, f is 0 or1, and the sum of d+e+f=5, and wherein the bicyclo[d.e.f]heptyl orbicyclo[d.e.f]heptenyl may, optionally, be substituted on one or more ofthe ring carbon atoms by one or more (C₁-C₆)alkyl groups,

R¹² is absent or is a bivalent linking group,R¹³ is bivalent polyether group, andR¹⁴ is absent or is a bivalent linking group.

Suitable bicycloheptyl- and bicycloheptenyl-moieties may be derivedfrom, for example, terpenic compounds having core (non-substituted) 7carbon atom bicyclic ring systems according to structures (D.II)-(D.VI):

More typically, R¹¹ is:

a bicyclo[2.2.1]heptyl or bicyclo[2.2.1]heptenyl group bonded to R², ifpresent, or to R³, if R² is not present, via its carbon atom at the2-position or 3-position and is typically substituted on its carbon atomat the 7 position by one or two (C₁-C₆)alkyl radicals, more typically bytwo methyl radicals, or

a bicyclo[3.1.1]heptyl or bicyclo[3.1.1]heptenyl group bonded to R², ifpresent, or to R³, if R² is not present, via its carbon atom at the2-position or 3-position and is typically substituted on its carbon atomat the 6-position or 7-position by one or two (C₁-C₆)alkyl radicals,more typically by two methyl radicals.

In another embodiment, R¹¹ is branched (C₅-C₅₀)alkyl group, moretypically a branched alkyl group according to structure (D.VIII):

wherein:

R¹⁵ and R¹⁶ are each independently (C₁-C₄₈)alkyl, anda is an integer of from 0 to 40,provided that R¹¹, that is, R¹⁵, R¹⁶ and the —(CH₂)_(a)— radical takentogether, comprises a total of from about 5 to about 50, more typicallyabout 12 to about 50, carbon atoms;R¹² is absent or is a bivalent linking group,R¹³ is bivalent polyether group, andR¹⁴ is absent or is a bivalent linking group.

More typically, R¹² is O, a bivalent hydrocarbon group, even moretypically a methylene group or chain of from 2 to 6 methylene units, ora bivalent alkyleneoxyl group, such as ethyleneoxy. In one embodiment,R¹² is according to structure (D.VIII):

—(CH₂)_(b)-A-  (D.IX)

wherein A is O or absent, and b is an integer of from 1 to 6.

More typically, R¹³ is a bivalent polyether group comprising a linearchain of from 2 to 100 units, each of which may independently be(C₂-C₄)oxyalkylene, more typically, (C₂-C₃)oxyalkylene. In oneembodiment, R¹³ is a bivalent polyether group comprising a chain of from2 to 100 polymerized oxyethylene units and oxypropylene units, which maybe arranged alternately, randomly, or in blocks. In one embodiment, R¹³is a bivalent polyether group comprising a block of polyoxyethyleneunits and a block of oxypropylene units, more typically, a block ofpolyoxyethylene units and a block of oxypropylene units, wherein theblock of oxypropylene units is disposed between and links the block ofoxyethylene units and the R¹² substituent, if present, or the R¹¹substituent, if R¹² is not present.

In one embodiment, R¹³ is according to structure (D.X):

wherein:g and h are independently integers of from 2 to 5, more typically 2 or3,each i is independently an integer of from 1 to about 80, more typicallyfrom 1 to about 50,each j is independently an integer of from 0 to about 80, more typicallyfrom 1 to about 50,k is an integer of from 1 to about 50, provided that the productobtained by multiplying the integer k times the sum of i+j is from 2 toabout 100.

If i≠0, j≠0, and g≠ h, the respective —(C_(p)H_(2p)O)— and(—(C_(q)H_(2q)O)— oxyalkylene units may be arranged randomly, in blocks,or in alternating order.

In one embodiment,

g=2,

h=3,

i is an integer of from 1 to 50, more typically 10 to 40, and even moretypically from 15 to about 30,

j is an integer of from 1 to 30, more typically from 2 to 20, and evenmore typically from about 2 to about 10, and

k=1.

In one embodiment, R¹⁴ is O, —(CH₂)_(n)—O—, or is according to structure(D.XI):

wherein:n is an integer of from 1 to 6,

A is O or NR¹⁷, and

R¹⁷ is H or (C₁-C₄)alkyl.

In another embodiment of structure (D.I) R¹¹ is a tri-styryl groupaccording to the following structure D.XII.

wherein R1, R2 and R3 are independently selected from the followingstructures D.XIIa, D.XIIb, D.XIIc, D.XIId.

The hydrophobic monomeric units may be made by known synthetictechniques, such as, for example, by grafting of one or more groupsaccording to structure (D.I) onto a polymer backbone, such as ahydrocarbon polymer backbone, a polyester polymer backbone, or apolysaccharide polymer backbone, or by copolymerization, with, forexample, the first acidic monomer, second acidic monomer and nonionicmonomer monomer described above, of at least one other monomer selectedfrom monomers that comprise a reactive functional group and at least onegroup according to structure (D.I) per molecule.

In one embodiment, the hydrophobic monomeric units are derived from atleast one hydrophobic monomer selected from monomers that comprise areactive functional group and at least one group according to structure(D.I) per molecule.

In one embodiment, the reactive functional group of the first monomer isan ethylenically unsaturated group. Thus, the hydrophobic monomer isselected from ethylenically unsaturated monomers that comprise at leastone site of ethylenic unsaturation, more typically, an α-, β-unsaturatedcarbonyl moiety, and least one group according to structure (I) permolecule.

In one embodiment, the hydrophobic monomer comprises one or morecompounds according to structure (D.XIV):

R¹⁸-R¹⁴-R¹³-R¹²-R¹¹  (D.XIV)

wherein:

R¹¹, R¹², R¹³, and R¹⁴ are each as described above, and

R¹⁸ is a moiety having a site of ethylenic unsaturation.

In one embodiment, the compound according to structure (D.XI) is an α-,β-unsaturated carbonyl compound.

In one embodiment, R¹⁸ is according to structure (D.XV):

wherein R¹⁹ is H or (C₁-C₄)alkyl.

In one embodiment, the hydrophobic monomer is selected from monomersaccording to structure (D.XVI):

wherein:

R¹¹ is bicyclo[d.e.f]heptyl or bicyclo[d.e.f]heptenyl wherein d is 2, 3,or 4, e is 1 or 2, f is 0 or 1, and the sum of d+e+f=5, and which may,optionally, be substituted on one or more of the ring carbon atoms byone or more (C₁-C₆)alkyl groups, or R¹¹ is a tri-styryl group accordingto the above-discussed structure D.XII.

andR¹⁹, b, g, h, i, j, and k are each as defined above, namely:R¹⁹ is H or (C₁-C₄)alkyl,b is an integer of from 1 to 6,g and h are independently integers of from 2 to 5, more typically 2 or3, each i is independently an integer of from 1 to about 80, moretypically from 1 to about 50,each j is independently an integer of from 0 to about 80, more typicallyfrom 1 to about 50,k is an integer of from 1 to about 50, provided that the productobtained by multiplying the integer k times the sum of i+j is from 2 toabout 100.

Preferably R¹¹ is the bicyclo[d.e.f]heptyl or bicyclo[d.e.f]heptenylgroup.

In another embodiment of monomers according to structure (D.XVI) R¹¹ isa tri-styryl group according to the following structure D.XII and R¹⁹,b, g, h, j, and k are each as defined above. An example of a suitablemonomer has structure D.XVia:

In one embodiment, the hydrophobic monomer comprises one or morecompounds according to structure (D.XVII):

wherein i, j, and R¹⁹ are each as described above, and, more typically,i is an integer of from 10 to 40, and even more typically from 15 toabout 30, or from about 20 to about 30, and j is an integer of from 1 to20, and even more typically from about 2 to about 10. A preferredversion of this structure has the structure D.XVIIa:

In another embodiment, the hydrophobic monomer comprises one or morecompounds according to structure (D.XVIII):

wherein a, i, j, and R¹⁵, R¹⁶, and R¹⁹ are each as described above.

Suitable hydrophobic monomer may be made by known synthetic methods. Forexample, a bicycloheptenyl intermediate compound (D.XIX), known as“Nopol”:

is made by reacting β-pinene with formaldehyde, and

a bicycloheptyl intermediate compound (D.XX), known as “Arbanol”:

is made by isomerization of α-pinene to camphene and ethoxyhydroxylationof the camphene.

The bicycloheptyl- or bicycloheptenyl-intermediate may then bealkoxylated by reacting the bicycloheptyl- or bicycloheptenylintermediate with one or more alkylene oxide compounds, such as ethyleneoxide or propylene oxide, to form a bicycloheptyl-, orbicycloheptenyl-polyether intermediate. The alkoxylation may beconducted according to well known methods, typically at a temperature inthe range of about 100° to about 250° C. and at a pressure in the rangeof from about 1 to about 4 bars, in the presence of a catalyst, such asa strong base, an aliphatic amine, or a Lewis acid, and an inert gas,such as nitrogen or argon.

The bicycloheptyl-, or bicycloheptenyl-polyether monomer may then beformed from the bicycloheptyl- or bicycloheptenyl-polyether intermediateby addition of a moiety containing an ethylenically unsaturated group tothe bicycloheptyl- or bicycloheptenyl-polyether intermediate, by, forexample, esterification, under suitable reaction conditions, of thebicycloheptyl- or bicycloheptenyl-polyether intermediate with, forexample, methacrylic anhydride.

Alternatively, a monomer comprising a ethylenically unsaturated group,such as for example, a polyethylene glycol monomethacrylate, which mayoptionally be further alkoxylated, may be reacted with thebicycloheptyl- or bicycloheptenyl-intermediate to form thebicycloheptyl-, or bicycloheptenyl-polyether monomer.

In another embodiment, the hydrophobic monomeric units eachindependently comprise, per monomeric unit, at least one group accordingto structure (D.XXI):

—R²³-R²²-R²¹  (D.XXI)

wherein:R²¹ is linear or branched (C₅-C₅₀)alkyl, hydroxyalkyl, alkoxyalkyl,aryl, or aryalkyl,R²² is a bivalent polyether group,R²³ is absent or is a bivalent linking group.

In one embodiment, R²¹ is linear or branched (C₅-C₄₀)alkyl, moretypically linear or branched (C₁₀-C₄₀)alkyl, even more typically, linearor branched (C₁₆-C₄₀)alkyl, and still more typically linear or branched(C₁₆-C₃₀)alkyl. In one embodiment, R²¹ is tridecyl, tetradecyl,pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl,heneicosyl, behenyl, tricosyl, tetracosyl, pentacosyl, hexacosyl,heptacosyl, octacosyl, nonacosyl, triacontyl, dotriacontyl,tritriacontyl, tetratriacontyl, pentatriacontyl, hexatriacontyl,heptatriacontyl, octatriacontyl, nonatriacontyl, or tetracontyl, moretypically, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, orbehenyl.

In embodiment R²¹ is hydroxyalkyl, such as, for example,hydroxyhexadecyl, hydroxyoctadecyl, or hydroxyeicosyl, or alkoxyalkyl,such as for example, methoxyhexadecyl, methoxyoctadecyl, ormethoxyeicosyl.

In embodiment R²¹ is aryl, such as, for example, phenyl, methylphenyl,methoxyphenyl, dibutylphenyl, triisobutylphenyl, or tristyrylphenyl, orarylalkyl, such as phenylmethyl, phenylethyl, or triphenylmethyl.

In one embodiment, the hydrophobic monomeric units each independentlycomprise at least one group according to structure (D.XVIII) abovewherein R²¹ is a linear (C₅-C₅₀)alkyl group.

In one embodiment, the hydrophobic monomeric units each independentlycomprise at least one group according to structure (D.XXI) above whereinR²¹ is a branched (C₅-C₅₀)alkyl group, more typically a branched(C₅-C₅₀)alkyl group according to structure (D.IX).

In one embodiment, the hydrophobic monomeric units comprise a mixture ofhydrophobic monomeric units that each independently comprise at leastone group according to structure (D.XXI) above wherein R²¹ is a linear(C₅-C₅₀)alkyl group and other hydrophobic monomeric units that eachindependently comprise at least one group according to structure (D.XXI)above wherein R²¹ is a branched (C₅-C₅₀)alkyl group, more typically abranched (C₅-C₅₀)alkyl group according to structure (D.VIII) above.

In one embodiment, R²² is a bivalent polyether group comprising a linearchain of from 2 to 100 units, each of which may independently be(C₂-C₄)oxyalkylene, more typically, (C₂-C₃)oxyalkylene. In oneembodiment, R²² is a bivalent polyether group comprising a chain of from2 to 100 polymerized oxyethylene units.

In one embodiment, R²² is according to structure (D.XXII):

wherein:p and q are independently integers of from 2 to 5, more typically 2 or3,each r is independently an integer of from 1 to about 80, more typicallyfrom 1 to about 50,each s is independently an integer of from 0 to about 80, more typicallyfrom 0 to about 50,t is an integer of from 1 to about 50, provided that the productobtained by multiplying the integer t times the sum of r+s is from 2 toabout 100.

If r≠0, s≠0, and p≠ q, the respective —(C_(p)H_(2p)O)— and—(C_(q)H_(2q)O)-oxyalkylene units may be arranged randomly, in blocks,or in alternating order.

In one embodiment,

p=2,

q=3,

r is an integer of from 1 to 50, more typically 5 to 45, and even moretypically from 10 to about 40,

s is an integer of from 1 to 30, more typically from 2 to 20, and evenmore typically from about 2 to about 10, and

t=1

In another embodiment,

p=2,

r is an integer of from 1 to 50, more typically 5 to 45, and even moretypically from 10 to about 40,

s is 0, and

t=1.

In one embodiment, R²³ is O, —(CH₂)_(n)—O— wherein n is an integer offrom 1 to 6, or is according to structure (D.X) above, wherein A is O orNR¹⁷, and R¹⁷ is H or (C₁-C₄)alkyl.

The hydrophobic monomeric units may be made by known synthetictechniques, for example, by grafting of one or more groups according tostructure D.XVII onto a polymer backbone, such as a hydrocarbon polymerbackbone, a polyester polymer backbone, or a polysaccharide polymerbackbone, or by copolymerization, with, for example, the above-describedfirst acidic monomer, second acidic monomer and the nonionic monomerdescribed above.

In one embodiment, the hydrophobic monomeric units are derived fromcopolymerizing at least one monomer that comprises a reactive functionalgroup and at least one group according to structure (D.XXI) permolecule.

In one embodiment, the reactive group of the hydrophobic monomer is anethylenically unsaturated group and the second monomer is anethylenically unsaturated monomer comprises at least one site ofethylenic unsaturation, more typically, an α-, β-unsaturated carbonylmoiety, and at least one group according to structure (D.XXI) permolecule and copolymerizable with the first monomer.

In one embodiment, the hydrophobic monomer comprises one or morecompounds according to structure (D.XXIII):

R²⁴-R²³-R²²-R²¹  (D.XXIII)

wherein:

R²¹, R²², and R²³ are each as described above, and

R²⁴ is a moiety having a site of ethylenic unsaturation. Thus theresulting hydrophobic monomeric unit has the structure (D.XXIV):

In one embodiment, the compound according to structure (D.XIX) is an α-,β-unsaturated carbonyl compound. In one embodiment, R²³ is according tostructure (D.X).

In one embodiment, the hydrophobic monomer comprises one or morecompounds according to structure (D.XXV):

wherein

R²¹ is linear or branched (C₅-C₅₀)alkyl, hydroxyalkyl, alkoxyalkyl,aryl, or arylalkyl,

-   -   R²⁵ is methyl or ethyl, and        p and q are independently integers of from 2 to 5, more        typically 2 or 3, each r is independently an integer of from 1        to about 80, more typically from 1 to about 50,        each s is independently an integer of from 0 to about 80, more        typically from 0 to about 50,        t is an integer of from 1 to about 50, provided that the product        obtained by multiplying the integer t times the sum of r+s is        from 2 to about 100; or p, q, r, s, and t are each as otherwise        described above.

In one embodiment, the hydrophobic monomer comprises one or morecompounds according to structure (D.XXV) wherein R²¹ is linear(C₁₆-C₂₂)alkyl.

In one embodiment, the hydrophobic monomer comprises one or morecompounds according to structure (D.XXV) wherein R²¹ is a branched(C₅-C₅₀)alkyl group, more typically a branched (C₅-C₅₀)alkyl groupaccording to structure (D.VII) above. For example R²¹ may have thestructure D.XXVI

wherein m and n each, independently, are positive integers from 1 to 39and m+n represents an integer from 4 to 40, as disclosed by US PatentApplication Publication 2006/02700563 A1 to Yang et al, incorporatedherein by reference.

In one embodiment, the hydrophobic monomer comprises one or morecompounds according to structure (D.XX) wherein p=2, s=0, and t=1.

In one embodiment, the hydrophobic monomer comprises one or morecompounds according to structure (D.XX) wherein R²¹ is linear(C₁₆-C₂₂)alkyl, R²⁵ is methyl or ethyl, p=2, s=0, and t=1.

Suitable ethylenically unsaturated hydrophobic monomers include:

alkyl-polyether (meth)acrylates that comprise at least one linear orbranched (C₅-C₄₀)alkyl-polyether group per molecule, such as hexylpolyalkoxylated (meth)acrylates, tridecyl polyalkoxylated(meth)acrylates, myristyl polyalkoxylated (meth)acrylates, cetylpolyalkoxylated (meth)acrylates, stearyl polyalkoxylated(methyl)acrylates, eicosyl polyalkoxylated (meth)acrylates, behenylpolyalkoxylated (meth)acrylates, melissyl polyalkoxylated(meth)acrylates, tristyrylphenoxyl polyalkoxylated (meth)acrylates, andmixtures thereof,

alkyl-polyether (meth)acrylamides that comprise at least one(C₅-C₄₀)alkyl-polyether substituent group per molecule, such as hexylpolyalkoxylated (meth)acrylamides, tridecyl polyalkoxylated(meth)acrylamides, myristyl polyalkoxylated (meth)acrylamides, cetylpolyalkoxylated (meth)acrylamides, stearyl polyalkoxylated(methyl)acrylamides, eicosyl polyalkoxylated (meth)acrylamides, behenylpolyalkoxylated (meth)acrylamides, melissyl polyalkoxylated(meth)acrylamides and mixtures thereof,

alkyl-polyether vinyl esters, alkyl-polyether vinyl ethers, oralkyl-polyether vinyl amides that comprise at least one(C₅-C₄₀)alkyl-polyether substituent group per molecule such as vinylstearate polyalkoxylate, myristyl polyalkoxylated vinyl ether, andmixtures thereof,

as well as mixtures of any of the above alkyl-polyether acrylates,alkyl-polyether methacrylates, alkyl-polyether acrylamides,alkyl-polyether methacrylamides, alkyl-polyether vinyl esters,alkyl-polyether vinyl ethers, and/or alkyl-polyether vinyl amides.

In one embodiment, the hydrophobic monomer comprises one or morealkyl-polyalkoxylated (meth)acrylates that comprise one linear orbranched (C₅-C₄₀)alkyl-polyethoxylated group, more typically(C₁₀-C₂₂)alkyl-polyethoxylated group per molecule, such asdecyl-polyethoxylated (meth)acrylates, tridecyl-polyethoxylated(meth)acrylates, myristyl-polyethoxylated (meth)acrylates,cetyl-polyethoxylated (meth)acrylates, stearyl-polyethoxylated(methyl)acrylates, eicosyl-polyethoxylated (meth)acrylates,behenyl-polyethoxylated (meth)acrylates, even more typicallydecyl-polyethoxylated methacrylates, tridecyl-polyethoxylatedmethacrylates, myristyl-polyethoxylated methacrylates,cetyl-polyethoxylated methacrylates, stearyl-polyethoxylatedmethylacrylates, eicosyl-polyethoxylated methacrylates,behenyl-polyethoxylated methacrylates, and mixtures thereof.

In one embodiment wherein the nonionic ethylenically unsaturatedhydrophobic monomer comprises a compound according to structure astructure selected from the group consisting of structure D.XXVIIa andstructure D.XXVIIb:

wherein R₃ is H or CH₃, R₄ is independently an alkyl chain containing 1to about 4 carbon atoms; R₅ is an alkyl chain containing 1 to about 6carbon atoms (preferably methyl); R₆ is an alkyl chain containing 1 toabout 4 carbon atoms; M is an integer from 0 to about 50 (preferablyabout 1 to 50, more preferably about 5 to 30); N is an integer from 0 to20 (preferably 1 to 20, more preferably 5 to 15); P is an integer from 0to about 50 (preferably 0 to 30); wherein P+M is greater than or equalto 1; wherein Q is an integer from 1 to 4 (typically 1 to 2).

Some typical hydrophobic monomers have any of the structures D.XXVIII,D.XXIX, D.XXX, or D.XXXI,

III. Making the ASE and/or HASE Copolymer

The pH responsive ASE copolymer is the product of copolymerization of amixture of monomers, comprising:

A. about 0.1-70 weight percent, typically 0.5-50, 0.7-40, 1-40, 5-40,5-30 or 10 to 40 weight percent of at least one alpha beta-ethylenicallyunsaturated first acid monomer selected from the group consisting ofmono-[2-(methacryloyloxy)ethyl]phthalate (also known as2-(2-carboxybenzoyloxy)ethyl methacrylate, MAEP) andmono-[2-(Methacryloyloxy)ethyl hexahydro]phthalate (MAHP),

B. about 0-45 weight percent, preferably 5 to 30 weight percent, of atleast one C3-C8 alpha beta-ethylenically unsaturated acidic monomer,preferably a C3-C8 alpha beta-ethylenically unsaturated carboxylic acidmonomer;

C. about 15-70 weight percent, typically 20 to 50 weight percent, of atleast one non-ionic, copolymerizable C2-C12 alpha, beta-ethylenicallyunsaturated monomer.

The pH responsive HASE copolymer is the product of copolymerization of amixture of monomers, comprising:

A. about 0.1-70 weight percent, typically 0.5-50, 0.7-40, 1-40, 5-40,5-30 or 10 to 40 weight percent of at least one alpha beta-ethylenicallyunsaturated first acid monomer selected from the group consisting ofmono-[2-(methacryloyloxy)ethyl]phthalate (also known as2-(2-carboxybenzoyloxy)ethyl methacrylate, MAEP) andmono-[2-(Methacryloyloxy)ethyl hexahydro]phthalate (MAHP),

B. about 0-45 weight percent, preferably 5 to 30 weight percent, of atleast one C3-C8 alpha beta-ethylenically unsaturated acidic monomer,preferably a C3-C8 alpha beta-ethylenically unsaturated carboxylic acidmonomer;

C. about 15-70 weight percent, typically 20 to 50 weight percent, of atleast one non-ionic, copolymerizable C2-C12 alpha, beta-ethylenicallyunsaturated monomer; and

D. about 0 to 30 weight percent, preferably 0.05 to 30 weight percent ortypically 5 to 20 weight percent, of at least one non-ionicethylenically unsaturated hydrophobic monomer.

In one embodiment, the pH responsive copolymer of the present inventionis the product of polymerization of a mixture of monomers comprising,based on the 100 pbw of the total amount of the monomers:

-   (a) from about 0.1, more typically from about 1 or 5 pbw of the    first acidic monomers, to about 70, more typically to about 40 pbw,    of the one or more first acidic monomers,-   (b) from about 0, more typically from about 1, and even more    typically from about 5, pbw of the second acidic monomers, to about    45, more typically to about 35, and even more typically to about 30,    pbw of the one or more second acidic monomers, and-   (c) from about 15, more typically from about 20 pbw of the one or    more nonionic acidic monomers, to about 70, more typically to about    50 pbw, of the one or more nonionic monomers, and-   (d) from about 0, more typically from about 0.05, even more    typically from about 1, and still more typically from about 5, pbw    of the one or more hydrophobic monomers, to about 30, more typically    to about 25, and even more typically to about 20, pbw of the one or    more hydrophobic monomers.

The pH responsive copolymer of the present invention can be convenientlyprepared from the above-described monomers by known aqueous emulsionpolymerization techniques using free-radical producing initiators,typically in an amount from 0.01 percent to 3 percent, based on theweight of the monomers.

In one embodiment, the polymerization is conducted at a pH of about 5.0or less. Polymerization at an acid pH of about 5.0 or less permitsdirect preparation of an aqueous colloidal dispersion having relativelyhigh solids content without the problem of excessive viscosity.

In one embodiment, the polymerization is conducted in the presence ofone or more free-radical producing initiators selected from peroxygencompounds. Useful peroxygen compounds include inorganic persulfatecompounds such as ammonium persulfate, potassium persulfate, sodiumpersulfate, peroxides such as hydrogen peroxide, organic hydroperoxides,for example, cumene hydroperoxide, and t-butyl hydroperoxide, organicperoxides, for example, benzoyl peroxide, acetyl peroxide, lauroylperoxide, peracetic acid, and perbenzoic acid (sometimes activated by awater-soluble reducing agent such as ferrous compound or sodiumbisulfite), and other free-radical producing materials or techniquessuch as 2,2′-azobisisobutyronitrile and high energy radiation sources.

In one embodiment, the polymerization is conducted in the presence ofone or more emulsifiers. Useful emulsifiers include anionic surfactants,nonionic surfactants, amphoteric surfactants, and zwitterionicsurfactants. In one embodiment, the emulsion polymerization is conductedin the presence of one or more anionic surfactants. Examples of anionicemulsifiers are the alkali metal alkyl aryl sulfonates, the alkali metalalkyl sulfates and the sulfonated alkyl esters. Specific examples ofthese well-known emulsifiers are sodium dodecyl benzene sulfonate,sodium dodecyl butylnaphthalene sulfonate, sodium lauryl sulfate,disodium dodecyl diphenyl ether disulfonate, disodium n-octadecylsulfosuccinamate and sodium dioctyl sulfosuccinate. Known nonionicemulsifiers include, for example, fatty alcohols, alkoxylated fattyalcohols, and alkylpolyglucosides.

The emulsion polymerization may, optionally, be conducted in thepresence, in an amount up to about 10 parts per 100 parts ofpolymerizable monomers, of one or more chain transfer agents.Representative chain transfer agents are carbon tetrachloride,bromoform, bromotrichloromethane, and long-chain alkyl mercaptans andthioesters, such as n-dodecyl mercaptan, t-dodecyl mercaptan, octylmercaptan, tetradecyl mercaptan, hexadecyl mercaptan, butylthioglycolate, isooctyl thioglycolate, and dodecyl thioglycolate.

Optionally, other ingredients well known in the emulsion polymerizationart may be included, such as chelating agents, buffering agents,inorganic salts and pH adjusting agents.

In one embodiment, the polymerization is carried out at a temperaturebetween about 60° C. and 90° C., but higher or lower temperatures may beused. The polymerization can be conducted batchwise, stepwise, orcontinuously with batch and/or continuous addition of the monomers, in aconventional manner.

The monomers can be copolymerized in such proportions, and the resultingemulsion polymers can be physically blended, to give products with thedesired balance of properties for specific applications. For example,for analogous polymers of a given molecular weight, increasing theamount of first monomer tends to increase the yield strength exhibitedby the polymer, increasing the relative amount of second monomer tendsto increase the viscosity of the polymer. One or more fourth monomersmay be added to adjust the properties of the polymer.

These polymeric products prepared by emulsion polymerization at an acidpH are in the form of stable aqueous colloidal dispersions containingthe polymer dispersed as discrete particles having average particlediameters of about 400 to about 3000 Å (40 to 300 nanometers) andpreferably about 600 to about 1750 Å (60 to 175 nanometers), as measuredby light scattering. Dispersions containing polymer particles smallerthan about 400 Å (40 nanometers) are difficult to stabilize, whileparticles larger than about 3000 Å (300 nanometers) reduce the ease ofdispersion in the aqueous products to be thickened.

In one embodiment, the polymer composition is in the form of an aqueouspolymer dispersion, typically having a solids content including thepolymer and any surfactants that may be present and based on the totalweight of the polymer dispersion, of up to about 60 wt % and, moretypically about 20 to about 50 wt %.

Alternatively this (co)polymerization may also be conducted by differentmethods or in different solvents. The scope of methods and solvents iswell known to those skilled in the art.

Thus, these polymers for use in the present invention can be made usingknown solution polymerization techniques, wherein the reactant monomersand initiator are dissolved in an appropriate solvent such as toluene,xylene, tetrahydrofuran, or mixtures thereof. Polymerization can beaccomplished in the time and at the temperature necessary, e.g., 60° C.to 80° C. and about 2 to 24 hours. The polymer product can be isolatedthrough normal separation techniques, including solvent stripping.

In one embodiment, these polymers for use in the present inventionexhibit a weight average molecular weight, as determined by gelpermeation chromatography and light scattering of a solution of thepolymer in tetrahydrofuran and compared to a polystyrene standard, ofgreater than or equal to 30,000 grams per mole (“g/mole”). HASEthickeners may not fully dissolve in THF but after hydrolysis they candissolve in water and measurement can be run in a water gel permeationchromatography (GPC). Reference: Macromolecules 2000, 33, 2480. Forexample in a range of 30,000 to 5,000,000 g/mole. More typically thepolymer of the present invention exhibits a weight average molecularweight of from about 100,000 g/mole, and even more typically from about150,000 g/mole, to about 1,500,000 g/mole, more typically to about1,000,000 g/mole, and even more typically to about 800,000 g/mole.

In one embodiment, these pH responsive copolymers for use in the presentinvention are in the form of an aqueous colloidal polymer dispersion.When the polymer composition is in the form of an aqueous colloidalpolymer dispersion, the composition is maintained at a pH of about 5 orless to maintain stability. More typically, the aqueous colloidalpolymer dispersion composition has a pH of about 1.5 to about 3. Whenthickening of the composition is desired, the pH of the composition canbe increased to a value above about 5 by addition of a base tosolubilize the polymer.

These ASE and HASE copolymers and compositions for use as thickeners inthe present invention are pH-responsive. At the lower pH levels at whichthe emulsion polymerization takes place, i.e., pH levels of 5 or less,the composition is relatively thin or non-viscous. When the pH of thecopolymer dispersion is neutralized or adjusted by addition of a base toa pH of about 5.5 or more, preferably about 6 to about 11, thecomposition thickens substantially. The composition turns fromsemi-opaque or opaque to translucent or transparent as viscosityincreases. Viscosity increases as copolymer dissolves partially orcompletely in the aqueous phase of the composition. Neutralization canoccur in situ when the emulsion copolymer is blended with the base andadded to the aqueous phase. Or, if desired for a given application,neutralization can be carried out when blending with an aqueous product.Useful bases include, but are not limited to, ammonium hydroxide, anamine, sodium hydroxide, potassium carbonate or the like.

For example, the HASE copolymer having a polymer backbone including MAAand EA is a pH-sensitive thickener. Typically the copolymer is a latexat pH=2.3. When neutralized with a suitable base to a pH above about5.5, the carboxyl groups on the methacrylic acid ionize to carboxylateions. The charge on the polymer induces a conformational change, and thewhite latex becomes water-soluble, thus increasing the hydrodynamicvolume of the polymer. When the HASE copolymers swell, the pendanthydrophobic groups are free to build associations with one another andwith other hydrophobes available in the formulation, such assurfactants, particulates, emulsion droplets and dyes. This phenomenoncreates a network structure that results in a significant viscositybuild.

IV. Uses of the pH Responsive Polymer

The polymers and polymer compositions according to the present inventionare useful as water-soluble thickeners for a wide variety ofapplications ranging from home care, personal care and oilfield drillingfluids. They are particularly useful for aqueous paints and coatings.Solution-polymerized polymers can be used in solvent systems oremulsified by known techniques for use in aqueous systems. Other usesinclude latexes and detergents. Useful cosmetic compositions willtypically have an aqueous carrier, a pigment and/or cosmetic active, aHASE emulsion polymer, and optional adjuvants. Useful detergents andcleansers will typically have aqueous carrier, a HASE emulsion polymer,and optional adjuvants. Oilfield drilling fluids will typically have anaqueous carrier, HASE emulsion polymer as a thickener/viscositymodifier, and optional adjuvants. The oilfield drilling fluids areinjected into the oilfield formation. Useful latex coatings willtypically have an aqueous carrier, a HASE emulsion polymer, and optionaladjuvants.

The HASE emulsion polymers according to the present invention asdescribed herein are particularly useful as thickeners for a widevariety of water-based compositions. Such compositions include brine,slurries, and colloidal dispersions of water-insoluble inorganic andorganic materials, such as natural rubber, synthetic or artificiallatexes. The emulsion polymers of the invention are especially useful inareas requiring thickening at neutral pHs, such as in cosmetics.

In one embodiment, the aqueous composition comprising the pH responsivepolymer of the present invention exhibits viscoelastic properties atneutral to alkaline pH values, typically at pH values greater than orequal to about 5, more typically greater than or equal to about 5.5,even more typically from about 6 to about 9.

V. Use of the pH Responsive Polymer with Binders which are LatexPolymers

Embodiments of the invention, such as latex paint, may contain more thanone category of latex. There can be a first latex namely, the HASEcopolymer, as a thickener. There can also be a second latex, for exampleRHOPLEX SG30 or REVACRYL synthetic latex emulsion resins, as a binderfor latex paint.

Synthetic latexes take the form of aqueous dispersions/suspensions ofparticles of latex polymers. Synthetic latexes include aqueous colloidaldispersions of water-insoluble polymers prepared by emulsionpolymerization of one or more ethylenically unsaturated monomers.Typical of such synthetic latexes are emulsion copolymers ofmonoethylenically unsaturated compounds, such as styrene, methylmethacrylate, acrylonitrile with a conjugated diolefin, such asbutadiene or isoprene; copolymers of styrene, acrylic and methacrylicesters, copolymers of vinyl halide, vinylidene halide, vinyl acetate andthe like. Many other ethylenically unsaturated monomers or combinationsthereof can be emulsion polymerized to form synthetic latexes. Suchlatexes are commonly employed in paints (latex paints) and coatings. Thecomposition of the present invention may be added to latexes tomodify/increase viscosity.

The polymeric thickeners of this invention are advantageous for use withthe water-based compositions according to the foregoing description andwith compositions containing those materials, especially coatingcompositions of various types. Mixtures or combinations of two or morethickeners may be used, if desired. Of course the latex polymers used incoating compositions are preferably film-forming at temperatures about25 degrees C. or less, either inherently or through the use ofplasticizers. Such coating compositions include water-based consumer andindustrial paints; sizing, adhesives and other coatings for paper,paperboard, textiles; and the like.

Latex paints and coatings may contain various adjuvants, such aspigments, fillers and extenders. Useful pigments include, but are notlimited to, titanium dioxide, mica, and iron oxides. Useful fillers andextenders include, but are not limited to, barium sulfate, calciumcarbonate, clays, talc, and silica. The compositions of the presentinvention described herein are compatible with most latex paint systemsand provide highly effective and efficient thickening.

The polymer compositions of the present invention may be added toaqueous product systems at a wide range of amounts depending on thedesired system properties and end use applications. In latex paints, thecomposition is added such that the emulsion (HASE) polymer according tothe present invention is present at about 0.05 to about 5.0 weightpercent and preferably about 0.1 to about 3.0 weight percent based ontotal weight of the latex paint, including all of its components, suchas water, HASE polymer, latex polymer, pigment, and any adjuvants.

The present invention also includes a method of preparing an aqueouscoating composition by mixing together at least one latex polymerderived from at least one monomer and blended with at least one pHresponsive copolymer as described above, and at least one pigment.Preferably, the latex polymer is in the form of latex polymerdispersion. The additives discussed above can be added in any suitableorder to the latex polymer, the pigment, or combinations thereof, toprovide these additives in the aqueous coating composition. In the caseof paint formulations, the aqueous coating composition preferably has apH of from 7 to 10.

In formulating latexes and latex paints/coatings, physical propertiesthat may be considered include, but are not limited to, viscosity versusshear rate, ease of application to surface, spreadability, and shearthinning.

VI. Emulsion Polymerization to Make Latex Binder for Latex Paint

Emulsion polymerization is discussed in G. Pohlein, “EmulsionPolymerization”, Encyclopedia of Polymer Science and Engineering, vol.6, pp. 1-51 (John Wiley & Sons, Inc., NY, N.Y., 1986), the disclosure ofwhich is incorporated herein by reference. Emulsion polymerization is aheterogeneous reaction process in which unsaturated monomers or monomersolutions are dispersed in a continuous phase with the aid of anemulsifier system and polymerized with free-radical or redox initiators.The product, a colloidal dispersion of the polymer or polymer solution,is called a latex.

The monomers typically employed in emulsion polymerization to make latexfor latex paint include such monomers as methyl acrylate, ethylacrylate, methyl methacrylate, butyl acrylate, 2-ethyl hexyl acrylate,other acrylates, methacrylates and their blends, acrylic acid,methacrylic acid, styrene, vinyl toluene, vinyl acetate, vinyl esters ofhigher carboxylic acids than acetic acid, e.g. vinyl versatate,acrylonitrile, acrylamide, butadiene, ethylene, vinyl chloride and thelike, and mixtures thereof. This is further discussed below in thesection entitled “Latex Monomers”.

In the above process, suitable initiators, reducing agents, catalystsand surfactants are well known in the art of emulsion polymerization.Typical initiators include ammonium persulfate (APS), hydrogen peroxide,sodium, potassium or ammonium peroxydisulfate, dibenzoyl peroxide,lauryl peroxide, ditertiary butyl peroxide, 2,2′-azobisisobutyronitrile,t-butyl hydroperoxide, benzoyl peroxide, and the like. Commonly usedredox initiation systems are described e.g., by A. S. Sarac in Progressin Polymer Science 24(1999), 1149-1204.

Suitable reducing agents are those which increase the rate ofpolymerization and include for example, sodium bisulfite, sodiumhydrosulfite, sodium formaldehyde sulfoxylate, ascorbic acid,isoascorbic acid, and mixtures thereof.

Suitable catalysts are those compounds which increase the rate ofpolymerization and which, in combination with the above-describedreducing agents, promote decomposition of the polymerization initiatorunder the reaction conditions. Suitable catalysts include transitionmetal compounds such as, for example, ferrous sulfate heptahydrate,ferrous chloride, cupric sulfate, cupric chloride, cobalt acetate,cobaltous sulfate, and mixtures thereof.

Emulsion polymerization occurs in the presence of an emulsifier.Typically the mixture contains 0.5 to 6 wt % emulsifier based on weightof latex monomers

Typical emulsifiers are ionic or non-ionic surfactants polymerizable ornon-polymerizable in the aqueous coating composition including latexpolymer. Suitable ionic and nonionic surfactants are alkyl polyglycolethers such as ethoxylation products of lauryl, tridecyl, oleyl, andstearyl alcohols; alkyl phenol polyglycol ethers such as ethoxylationproducts of octyl- or nonylphenol, diisopropyl phenol, triisopropylphenol; alkali metal or ammonium salts of alkyl, aryl or alkylarylsulfonates, sulfates, phosphates, and the like, including sodium laurylsulfate, sodium octylphenol glycolether sulfate, sodium dodecylbenzenesulfonate, sodium lauryldiglycol sulfate, and ammonium tritertiarybutylphenol and penta- and octa-glycol sulfonates, sulfosuccinate salts suchas disodium ethoxylated nonylphenol half ester of sulfosuccinic acid,disodium n-octyldecyl sulfosuccinate, sodium dioctyl sulfosuccinate, andthe like.

The polymer latex binder can be produced by first preparing an initiatorsolution comprising the initiator and water. A monomer pre-emulsion isalso prepared comprising one or more surfactants (emulsifiers), andother latex monomers to be used to form the latex polymer, water, andadditional additives such as NaOH.

Thus, a typical process of emulsion polymerization preferably involvescharging water to a reactor and feeding as separate streams apre-emulsion of the monomer and a solution of the initiator. Inparticular, the polymer latex binder can be prepared using emulsionpolymerization by feeding the monomers used to form the latex binder toa reactor in the presence of at least one initiator and at least onesurfactant and polymerizing the monomers to produce the latex binder.Typically the initiator solution and monomer pre-emulsion arecontinuously added to the reactor over a predetermined period of time(e.g. 1.5-5 hours) to cause polymerization of latex monomers to producethe latex polymer.

Prior to the addition of the initiator solution and the monomerpre-emulsion, a seed latex such as a polystyrene seed latex can be addedto the reactor. For example, a small amount of the pre-emulsion and aportion of the initiator may be charged initially at the reactiontemperature to produce “seed” latex. The “seed” latex procedure resultsin better particle-size reproducibility.

Under “normal” initiation conditions, that is initiation conditionsunder which the initiator is activated by heat, the polymerization isnormally carried out at about 60-90° C. A typical “normal” initiatedprocess, for example, could employ ammonium persulfate as initiator at areaction temperature of 80+/−2° C. Under “redox” initiation conditions,namely initiation conditions under which the initiator is activated by areducing agent, the polymerization is normally carried out at 60-70° C.Normally, the reducing agent is added as a separate solution. A typical“redox” initiated process, for example, could employ potassiumpersulfate as the initiator and sodium metabisulfite as the reducingagent at a reaction temperature of 65+/−2° C.

The reactor is operated at desired reaction temperature at least untilall the monomers are fed to produce the polymer latex binder. Once thepolymer latex binder is prepared, it is preferably chemically strippedthereby decreasing its residual monomer content. Preferably, it ischemically stripped by continuously adding an oxidant such as a peroxide(e.g. t-butylhydroperoxide) and a reducing agent (e.g. sodium acetonebisulfite), or another redox pair such as those described by A. S. Saracin Progress in Polymer Science 24(1999), 1149-1204, to the latex binderat an elevated temperature and for a predetermined period of time (e.g.0.5 hours). The pH of the latex binder can then be adjusted and otheradditives added after the chemical stripping step.

In the above emulsions, the polymer preferably exists as a generallyspherical particle, dispersed in water, with a diameter of about 50nanometers to about 500 nanometers.

For purposes of this description, monomers from which latex polymers maybe derived are termed “latex monomers”.

The latex monomers fed to a reactor to prepare the polymer latex binderpreferably include at least one acrylic monomer selected from the groupconsisting of acrylic acid, acrylic acid esters, methacrylic acid, andmethacrylic acid esters. In addition, the monomers can include styrene,vinyl acetate, or ethylene. The monomers can also include one or moremonomers selected from the group consisting of styrene, (alpha)-methylstyrene, vinyl chloride, acrylonitrile, methacrylonitrile, ureidomethacrylate, vinyl acetate, vinyl esters of branched tertiarymonocarboxylic acids (e.g. vinyl esters commercially available under themark VEOVA from Shell Chemical Company or sold as EXXAR neo vinyl estersby ExxonMobil Chemical Company), itaconic acid, crotonic acid, maleicacid, fumaric acid, and ethylene. It is also possible to include C4-C8conjugated dienes such as 1,3-butadiene, isoprene or chloroprene.Commonly used monomers in making acrylic paints are butyl acrylate,methyl methacrylate, ethyl acrylate and the like. Preferably, themonomers include one or more monomers selected from the group consistingof n-butyl acrylate, methyl methacrylate, styrene and 2-ethylhexylacrylate.

The latex polymer is typically selected from the group consisting ofpure acrylics (comprising acrylic acid, methacrylic acid, an acrylateester, and/or a methacrylate ester as the main monomers); styreneacrylics (comprising styrene and acrylic acid, methacrylic acid, anacrylate ester, and/or a methacrylate ester as the main monomers); vinylacrylics (comprising vinyl acetate and acrylic acid, methacrylic acid,an acrylate ester, and/or a methacrylate ester as the main monomers);and acrylated ethylene vinyl acetate copolymers (comprising ethylene,vinyl acetate and acrylic acid, methacrylic acid, an acrylate ester,and/or a methacrylate ester as the main monomers). The monomers can alsoinclude other main monomers such as acrylamide and acrylonitrile, andone or more functional monomers such as itaconic acid and ureidomethacrylate, as would be readily understood by those skilled in theart. In a particularly preferred embodiment, the latex polymer is a pureacrylic such as a butyl acrylate/methyl methacrylate copolymer derivedfrom monomers including butyl acrylate and methyl methacrylate.

In typical acrylic paint compositions the polymer is comprised of one ormore esters of acrylic or methacrylic acid, typically a mixture, e.g.about 50/50 by weight, of a high T_(g) monomer (e.g. methylmethacrylate) and a low T_(g) monomer (e.g. butyl acrylate), with smallproportions, e.g. about 0.5% to about 2% by weight, of acrylic ormethacrylic acid. The vinyl-acrylic paints usually include vinyl acetateand butyl acrylate and/or 2-ethyl hexyl acrylate and/or vinyl versatate.In vinyl-acrylic paint compositions, at least 50% of the polymer formedis comprised of vinyl acetate, with the remainder being selected fromthe esters of acrylic or methacrylic acid. The styrene/acrylic polymersare typically similar to the acrylic polymers, with styrene substitutedfor all or a portion of the methacrylate monomer thereof.

The latex polymer dispersion preferably includes from about 30 to about75% solids and a mean latex particle size of from about 70 to about 650nm. The latex polymer is preferably present in the aqueous coatingcomposition in an amount from about 5 to about 60 percent by weight, andmore preferably from about 8 to about 40 percent by weight (i.e. theweight percentage of the dry latex polymer based on the total weight ofthe coating composition).

The aqueous coating composition is a stable fluid that can be applied toa wide variety of materials such as, for example, paper, wood, concrete,metal, glass, ceramics, plastics, plaster, and roofing substrates suchas asphaltic coatings, roofing felts, foamed polyurethane insulation; orto previously painted, primed, undercoated, worn, or weatheredsubstrates. The aqueous coating composition of the invention can beapplied to the materials by a variety of techniques well known in theart such as, for example, brush, rollers, mops, air-assisted or airlessspray, electrostatic spray, and the like.

VII. Liquid Carrier

In one embodiment, the composition of the present invention comprisesthe selected polymer and a liquid carrier.

In one embodiment, the liquid carrier is an aqueous carrier comprisingwater and the treatment solution is in the form of a solution, emulsion,or dispersion of the material and additives. In one embodiment, theliquid carrier comprises water and a water miscible organic liquid.Suitable water miscible organic liquids include saturated or unsaturatedmonohydric alcohols and polyhydric alcohols, such as, for example,methanol, ethanol, isopropanol, cetyl alcohol, benzyl alcohol, oleylalcohol, 2-butoxyethanol, and ethylene glycol, as well as alkyletherdiols, such as, for example, ethylene glycol monoethyl ether, propyleneglycol monoethyl ether and diethylene glycol monomethyl ether.

As used herein, terms “aqueous medium” and “aqueous media” are usedherein to refer to any liquid medium of which water is a majorcomponent. Thus, the term includes water per se as well as aqueoussolutions and dispersions.

VIII. Other Additives

As described above, latex paints and coatings may contain variousadjuvants.

The aqueous coating compositions of the invention include less than 2%by weight and preferably less than 1.0% by weight of anti-freeze agentsbased on the total weight of the aqueous coating composition. Forexample, the aqueous coating compositions may be substantially free ofanti-freeze agents.

The aqueous coating composition typically includes at least one pigment.The term “pigment” as used herein includes non-film-forming solids suchas pigments, extenders, and fillers. The at least one pigment ispreferably selected from the group consisting of TiO2 (in both anastaseand rutile forms), clay (aluminum silicate), CaCO3 (in both ground andprecipitated forms), aluminum oxide, silicon dioxide, magnesium oxide,talc (magnesium silicate), barytes (barium sulfate), zinc oxide, zincsulfite, sodium oxide, potassium oxide and mixtures thereof. Suitablemixtures include blends of metal oxides such as those sold under themarks MINEX (oxides of silicon, aluminum, sodium and potassiumcommercially available from Unimin Specialty Minerals), CELITES(aluminum oxide and silicon dioxide commercially available from CeliteCompany), ATOMITES (commercially available from English China ClayInternational), and ATTAGELS (commercially available from Engelhard).More preferably, the at least one pigment includes TiO2, CaCO3 or clay.Generally, the mean particle sizes of the pigments range from about 0.01to about 50 microns. For example, the TiO2 particles used in the aqueouscoating composition typically have a mean particle size of from about0.15 to about 0.40 microns. The pigment can be added to the aqueouscoating composition as a powder or in slurry form. The pigment ispreferably present in the aqueous coating composition in an amount fromabout 5 to about 50 percent by weight, more preferably from about 10 toabout 40 percent by weight.

The coating composition can optionally contain additives such as one ormore film-forming aids or coalescing agents. Suitable firm-forming aidsor coalescing agents include plasticizers and drying retarders such ashigh boiling point polar solvents. Other conventional coating additivessuch as, for example, dispersants, additional surfactants (i.e. wettingagents), rheology modifiers, defoamers, thickeners, additional biocides,additional mildewcides, colorants such as colored pigments and dyes,waxes, perfumes, co-solvents, and the like, can also be used inaccordance with the invention. For example, non-ionic and/or ionic (e.g.anionic or cationic) surfactants can be used to produce the polymerlatex. These additives are typically present in the aqueous coatingcomposition in an amount from 0 to about 15% by weight, more preferablyfrom about 1 to about 10% by weight based on the total weight of thecoating composition.

The aqueous coating composition typically includes less than 10.0% ofanti-freeze agents based on the total weight of the aqueous coatingcomposition. Exemplary anti-freeze agents include ethylene glycol,diethylene glycol, propylene glycol, glycerol (1,2,3-trihydroxypropane),ethanol, methanol, 1-methoxy-2-propanol, 2-amino-2-methyl-1-propanol,and FTS-365 (a freeze-thaw stabilizer from Inovachem SpecialtyChemicals). More preferably, the aqueous coating composition includesless than 5.0% or is substantially free (e.g. includes less than 0.1%)of anti-freeze agents. Accordingly, the aqueous coating composition ofthe invention preferably has a VOC level of less than about 100 g/L andmore preferably less than or equal to about 50 g/L.

The balance of the aqueous coating composition of the invention iswater. Although much of the water is present in the polymer latexdispersion and in other components of the aqueous coating composition,water is generally also added separately to the aqueous coatingcomposition. Typically, the aqueous coating composition includes fromabout 10% to about 85% by weight and more preferably from about 35% toabout 80% by weight water. Stated differently, the total solids contentof the aqueous coating composition is typically from about 15% to about90%, more preferably, from about 20% to about 65%.

The coating compositions are typically formulated such that the driedcoatings comprise at least 10% by volume of dry polymer solids, andadditionally 5 to 90% by volume of non-polymeric solids in the form ofpigments. The dried coatings can also include additives such asplasticizers, dispersants, surfactants, rheology modifiers, defoamers,thickeners, additional biocides, additional mildewcides, colorants,waxes, and the like, that do not evaporate upon drying of the coatingcomposition.

Biocides are substances that kill or inhibit the growth ofmicroorganisms such as bacteria, fungi and algae. Biocides includechlorinated hydrocarbons, organometallics, halogen-releasing compounds,metallic salts, quaternary ammonium compounds, phenolics and organicsulfur compounds.

Exemplary of organic sulfur compounds are compounds based on anisothiazolinone or isothiazolothione structure. The biocidal activity ofthese compounds is effected by inactivation of essential enzymes ofmicrobial metabolism which require sulfhydryl groups for activity. Theseenzymes include phosphoenolpyruvate transphosphorase and a number ofdehydrogenases. The thio moiety of the isothiazolinone orisothiazolothione compounds reacts with the free sulfhydryl groups of anenzyme to form a disulfide bond between the enzyme molecule and theisothiazolinone or isothiazolothione molecule rendering the sulfhydrylunavailable for interaction with substrate or effector molecules.

Isothiazolinone and isothiazolothione biocides have found widespread useas latex preservatives. Most latex emulsions are water based and areprone to microbial attack. Biocides are typically added to the finishedlatex after all processing is completed to protect the latex frommicrobial attack. The present compositions and methods may also includeIsothiazolinone biocides. Biocides which are widely used as latexpreservatives include PROXEL GXL, having an active ingredient of1,2-benzisothiazolin-3-one (BIT), PROMEXAL W50, having an activeingredient of 2-methyl-4,5-trimethylene-4-isothiazolin-3-one, and KATHONLX, a blend of 5-chloro-2-methyl-4-isothiazolin-3-one and2-methyl-4-isothiazolin-3-one active ingredients.

Typical isothiazolinones or isothiazolothiones are represented by thegeneral formula (I):

or a salt or a complex thereof;

wherein X is oxygen or sulfur; R is hydrogen, a substituted orunsubstituted hydrocarbyl group, a substituted or unsubstitutedhydrocarbylthio group, a substituted or unsubstituted hydrocarbyloxygroup or a carbamoyl group; and each of A and D is independentlyhydrogen, a halogen atom, a cyano group, a substituted or unsubstitutedhydrocarbyl group or a direct bond to the other of A or D.

When R, A and D are, or contain, substituted hydrocarbyl groups, thesubstituents are preferably independently halogen, alkoxy or alkylthiowhere the alkyl groups contain 1 to 4 carbon atoms. If R is a carbamoylgroup, preferably it is of the general type —CON(H)(R¹) where R¹ is ahydrogen atom or a hydrocarbyl group, which may be substituted withhalogen, alkoxy or alkylthio substituents. It is generally preferredthat R is a hydrogen atom or a lower alkyl group of 1 to 4 carbon atoms.Most preferably, R is hydrogen or a methyl group.

Preferably, A and D, together with the carbon atoms to which they areattached, form a five- or six-membered substituted or unsubstitutedring. The ring substituents are preferably halogen, alkyl of 1 to 4carbon atoms, alkoxy of 1 to 4 carbon atoms or alkylthio of 1 to 4carbon atoms. The ring may contain a heteroatom such as a nitrogen atomreplacing a carbon atom. Most preferably, A and D form a hydrocarbonring such as benzene, cyclopentene or cyclohexene.

Alternatively, A and D are separate groups. Preferably, at least one ofA and D is not a hydrogen atom and most preferably, at least one of Aand D is a halogen atom or an alkyl group of 1 to 4 carbon atoms.

The biocidal isothiazolinone compounds include5-chloro-2-methyl-4-isothiazolin-3-one (where R is methyl, A is hydrogenand D is chlorine); 2-methyl-4-isothiazolin-3-one (where R is methyl andA and D are both hydrogen); 4,5-dichloro-2-methylisothiazolin-3-one(where R is methyl and A and D are both chlorine);2-n-octylisothiazolin-3-one (where R is n-octyl and A and D are bothhydrogen; 1,2-benzisothiazolin-3-one (where R is hydrogen and A and D,together with the carbon atoms to which they are attached, form abenzene ring); 4,5-trimethylene-4-isothiazolin-3-one (where R ishydrogen and A and D, together with the carbon atoms to which they areattached, form a cyclopentene ring) and2-methyl-4,5-trimethylene-4-isothiazolin-3-one (where R is methyl and Aand D, together with the carbon atoms to which they are attached, form acyclopentene ring).

A typical the biocidal compound of this family which may be used as theadditional biocidal compound in the present invention is one where R ishydrogen and A and D together form an unsubstituted 5- or 6-memberedhydrocarbon ring as in the compounds 1,2-benzisothiazolin-3-one and4,5-trimethylene-4-isothiazolin-3-one.

Certain of the isothiazolinone or isothiazolothione compounds which maybe used as the additional biocidal compound can have improved solubilityin water when ill the form of a salt or complex. The salt or complex maybe with any suitable cation such as an amine (including an alkanolamine)or a metal. Preferably, any metal salt or complex contains a monovalentmetal such as an alkali metal. The alkali metal may be lithium, sodiumor potassium. Most preferably, the alkali metal salt is a sodium salt inview of the ready availability of suitable sodium compounds from whichto prepare the salt.

Certain isothiazolinone or isothiazolothione compounds useful as thebiocidal compounds decompose in the presence of alkali. Exemplary ofalkali-sensitive compounds are 5-chloro-2-methyl-4-isothiazolin-3-oneand 2-methyl-4-isothiazolin-3-one. Accordingly, the pH of thecompositions of the present invention which are alkali sensitive shouldbe maintained at a value no greater than about 8.

IX. Personal Care

The pH responsive polymer of the present invention is suitable in thepreparation of personal care (cosmetics, toiletries, health and beautyaids, cosmeceuticals) and topical health care products, includingwithout limitation, hair care products, such as shampoos (includingcombination shampoos, such as “two-in-one” conditioning shampoos);post-shampoo rinses; setting and style maintenance agents includingsetting aids, such as gels and sprays, grooming aids, such as pomades,conditioners, perms, relaxers, hair smoothing products, and the like;skin care products (facial, body, hands, scalp and feet), such ascreams, lotions, conditioners, and cleansing products; anti-acneproducts; anti-aging products (exfoliant, keratolytic, anticellulite,antiwrinkle, and the like); skin protectants such as sunscreens,sunblock, barrier creams, oils, silicones, and the like; skin colorproducts (whiteners, lighteners, sunless tanning accelerators, and thelike); hair colorants (hair dyes, hair color rinses, highlighters,bleaches and the like); pigmented skin colorants (face and body makeups,foundation creams, mascara, rouge, lip products, and the like); bath andshower products (body cleansers, body wash, shower gel, liquid soap,soap bars, syndet bars, conditioning liquid bath oil, bubble bath, bathpowders, and the like); nail care products (polishes, polish removers,strengtheners, lengtheners, hardeners, cuticle removers, softeners, andthe like); and any aqueous acidic to basic composition to which aneffective amount of the hydrophobic polymer can be incorporated forachieving a beneficial or desirable, physical or chemical, effecttherein during storage and/or usage.

In one embodiment, the present invention is directed to a personal carecomposition comprising water, one or more surfactants, and a pHresponsive polymer according to the present invention.

In one embodiment, the personal care composition comprises, based on 100parts by weight (“pbw”) of the personal care composition, from about 10to about 80 pbw, more typically from about 20 to about 70 pbw, water,from about 1 to about 50 pbw of one or more surfactants and from about0.05 to about 20 pbw of the pH responsive polymer of the presentinvention.

Suitable surfactants include anionic surfactants, cationic surfactants,non-ionic surfactants, zwitterionic surfactants, and mixtures thereof.

Suitable anionic surfactants are known compounds and include, forexample, linear alkylbenzene sulfonates, alpha olefin sulfonates,paraffin sulfonates, alkyl ester sulfonates, alkyl sulfates, alkylalkoxy sulfates, alkyl sulfonates, alkyl alkoxy carboxylates, alkylalkoxylated sulfates, monoalkyl phosphates, dialkyl phosphates,sarcosinates, isethionates, and taurates, as well as mixtures thereof,such as for example, ammonium lauryl sulfate, ammonium laureth sulfate,triethanolamine laureth sulfate, monoethanolamine lauryl sulfate,monoethanolamine laureth sulfate, diethanolamine lauryl sulfate,diethanolamine laureth sulfate, lauric monoglyceride sodium sulfate,sodium lauryl sulfate, sodium laureth sulfate, potassium lauryl sulfate,potassium laureth sulfate, sodium trideceth sulfate, sodium tridecylsulfate, ammonium trideceth sulfate, ammonium tridecyl sulfate, sodiumcocoyl isethionate, disodium laureth sulfosuccinate, sodium methyloleoyl taurate, sodium laureth carboxylate, sodium tridecethcarboxylate, sodium monoalkyl phosphate, sodium dialkyl phosphate,sodium lauryl sarcosinate, lauroyl sarcosine, cocoyl sarcosinate,ammonium cocyl sulfate, sodium cocyl sulfate, potassium cocyl sulfate,monoethanolamine cocyl sulfate, sodium tridecyl benzene sulfonate,sodium dodecyl benzene sulfonate, and mixtures thereof.

The cationic counterion of the anionic surfactant is typically a sodiumcation but may alternatively be a potassium, lithium, calcium,magnesium, ammonium cation, or an alkyl ammonium anion having up to 6aliphatic carbon atoms, such as anisopropylammonium,monoethanolammonium, diethanolammonium, or triethanolammonium cation.Ammonium and ethanolammonium salts are generally more soluble than thesodium salts. Mixtures of the above cations may be used.

Suitable cationic surfactants are known compounds and include, forexample, mono-cationic surfactants according to structure (XX) below:

wherein:

R31, R32, R33 and R34 are independently hydrogen or an organic group,provided that at least one of R31, R32, R33 and R34 is not hydrogen, and

X⁻ is an anion, as well as mixtures of such compounds

If one to three of the R31, R32, R33 and R34 groups are each hydrogen,then the compound may be referred to as an amine salt. Some examples ofcationic amine salts include polyethoxylated (2) oleyl/stearyl amine,ethoxylated tallow amine, cocoalkylamine, oleylamine, and tallow alkylamine.

For quaternary ammonium compounds (generally referred to as quats) R31,R32, R33 and R34 may be the same or different organic group, but may notbe hydrogen. In one embodiment, R31, R32, R33 and R34 are each C8-C24branched or linear hydrocarbon groups which may comprise additionalfunctionality such as, for example, fatty acids or derivatives thereof,including esters of fatty acids and fatty acids with alkoxylated groups;alkyl amido groups; aromatic rings; heterocyclic rings; phosphategroups; epoxy groups; and hydroxyl groups. The nitrogen atom may also bepart of a heterocyclic or aromatic ring system, e.g., cetethylmorpholinium ethosulfate or steapyrium chloride.

Examples of quaternary ammonium compounds of the monoalkyl aminederivative type include: cetyl trimethyl ammonium bromide (also known asCETAB or cetrimonium bromide), cetyl trimethyl ammonium chloride (alsoknown as cetrimonium chloride), myristyl trimethyl ammonium bromide(also known as myrtrimonium bromide or Quaternium-13), stearyl dimethylbenzyl ammonium chloride (also known as stearalkonium chloride), oleyldimethyl benzyl ammonium chloride, (also known as olealkonium chloride),lauryl/myristryl trimethyl ammonium methosulfate (also known ascocotrimonium methosulfate), cetyl dimethyl (2)hydroxyethyl ammoniumdihydrogen phosphate (also known as hydroxyethyl cetyldimoniumphosphate), babassuamidopropalkonium chloride, cocotrimonium chloride,distearyldimonium chloride, wheat germ-amidopropalkonium chloride,stearyl octyldimonium methosulfate, isostearaminopropalkonium chloride,dihydroxypropyl PEG-5 linoleaminium chloride, PEG-2 stearmoniumchloride, Quaternium 18, Quaternium 80, Quaternium 82, Quaternium 84,behentrimonium chloride, dicetyl dimonium chloride, behentrimoniummethosulfate, tallow trimonium chloride and behenamidopropyl ethyldimonium ethosulfate.

Quaternary ammonium compounds of the dialkyl amine derivative typeinclude, for example, distearyldimonium chloride, dicetyl dimoniumchloride, stearyl octyldimonium methosulfate, dihydrogenatedpalmoylethyl hydroxyethylmonium methosulfate, dipalmitoylethylhydroxyethylmonium methosulfate, dioleoylethyl hydroxyethylmoniummethosulfate, hydroxypropyl bisstearyldimonium chloride, and mixturesthereof.

Quaternary ammonium compounds of the imidazoline derivative typeinclude, for example, isostearyl benzylimidonium chloride, cocoyl benzylhydroxyethyl imidazolinium chloride, cocoyl hydroxyethylimidazoliniumPG-chloride phosphate, Quaternium 32, and stearyl hydroxyethylimidoniumchloride, and mixtures thereof.

Typical cationic surfactants comprise dialkyl derivatives such asdicetyl dimonium chloride and distearyldimonium chloride; branchedand/or unsaturated cationic surfactants such asisostearylaminopropalkonium chloride or olealkonium chloride; long chaincationic surfactants such as stearalkonium chloride and behentrimoniumchloride; as well as mixtures thereof.

Suitable anionic counterions for the cationic surfactant include, forexample, chloride, bromide, methosulfate, ethosulfate, lactate,saccharinate, acetate and phosphate anions.

Suitable nonionic surfactants are known compounds and include amineoxides, fatty alcohols, alkoxylated alcohols, fatty acids, fatty acidesters, and alkanolamides. Suitable amine oxides comprise, (C10-C24)saturated or unsaturated branched or straight chain alkyl dimethyloxides or alkyl amidopropyl amine oxides, such as for example, lauramineoxide, cocamine oxide, stearamine oxide, stearamidopropylamine oxide,palmitamidopropylamine oxide, decylamine oxide as well as mixturesthereof. Suitable fatty alcohols include, for example, (C10-C24)saturated or unsaturated branched or straight chain alcohols, moretypically (C10-C20) saturated or unsaturated branched or straight chainalcohols, such as for example, decyl alcohol, lauryl alcohol, myristylalcohol, cetyl alcohol, stearyl alcohol, oleyl alcohol, linoleyl alcoholand linolenyl alcohol, and mixtures thereof. Suitable alkoxylatedalcohols include alkoxylated, typically ethoxylated, derivatives of(C10-C24) saturated or unsaturated branched or straight chain alcohols,more typically (C10-C20) saturated or unsaturated branched or straightchain alcohols, which may include, on average, from 1 to 22 alkoxylunits per molecule of alkoxylated alcohol, such as, for example,ethoxylated lauryl alcohol having an average of 5 ethylene oxide unitsper molecule. Mixtures of these alkoxylated alcohols may be used.Suitable fatty acids include (C10-C24) saturated or unsaturatedcarboxylic acids, more typically (C10-C22) saturated or unsaturatedcarboxylic acids, such as, for example, lauric acid, oleic acid, stearicacid, myristic acid, cetearic acid, isostearic acid, linoleic acid,linolenic acid, ricinoleic acid, elaidic acid, arichidonic acid,myristoleic acid, and palmitoleic acid, as well as neutralized versionsthereof. Suitable fatty acid esters include esters of (C10-C24)saturated or unsaturated carboxylic acids, more typically (C10-C22)saturated or unsaturated carboxylic acids, for example, propylene glycolisostearate, propylene glycol oleate, glyceryl isostearate, and glyceryloleate, and mixtures thereof. Suitable alkanolamides include aliphaticacid alkanolamides, such as cocamide MEA (coco monoethanolamide) andcocamide MIPA (coco monoisopropanolamide), as well as alkoxylatedalkanolamides, and mixtures thereof.

Suitable amphoteric surfactants are known compounds and include forexample, derivatives of aliphatic secondary and tertiary amines in whichthe aliphatic radical can be straight chain or branched and wherein oneof the aliphatic substituents contains from about 8 to about 18 carbonatoms and one contains an anionic water-solubilizing group as well asmixtures thereof. Specific examples of suitable amphoteric surfactantsinclude the alkali metal, alkaline earth metal, ammonium or substitutedammonium salts of alkyl amphocarboxy glycinates and alkylamphocarboxypropionates, alkyl amphodipropionates, alkylamphodiacetates, alkyl amphoglycinates, and alkyl amphopropionates, aswell as alkyl iminopropionates, alkyl iminodipropionates, and alkylamphopropylsulfonates, such as for example, cocoamphoacetatecocoamphopropionate, cocoamphodiacetate, lauroamphoacetate,lauroamphodiacetate, lauroamphodipropionate, lauroamphodiacetate,cocoamphopropyl sulfonate caproamphodiacetate, caproamphoacetate,caproamphodipropionate, and stearoamphoacetate.

In one embodiment, the amphoteric surfactant comprises sodiumlauroampoacetate, sodium lauroampopropionate, disodiumlauroampodiacetate, sodium cocoamphoacetate, disodium cocoamphodiacetateor a mixture thereof.

Suitable Zwitterionic surfactants are known compounds. Any Zwitterionicsurfactant that is acceptable for use in the intended end useapplication and is chemically stable at the required formulation pH issuitable as the optional Zwitterionic surfactant component of thecomposition of the present invention, including, for example, thosewhich can be broadly described as derivatives of aliphatic quaternaryammonium, phosphonium, and sulfonium compounds in which the aliphaticradicals can be straight chain or branched and wherein one of thealiphatic substituents contains from about 8 to about 24 carbon atomsand one contains an anionic water-solubilizing group such as carboxyl,sulfonate, sulfate, phosphate or phosphonate. Specific examples ofsuitable Zwitterionic surfactants include alkyl betaines, such ascocodimethyl carboxymethyl betaine, lauryl dimethyl carboxymethylbetaine, lauryl dimethyl alpha-carboxy-ethyl betaine, cetyl dimethylcarboxymethyl betaine, lauryl bis-(2-hydroxy-ethyl)carboxy methylbetaine, stearyl bis-(2-hydroxy-propyl)carboxymethyl betaine, oleyldimethyl gamma-carboxypropyl betaine, and laurylbis-(2-hydroxypropyl)alpha-carboxyethyl betaine, amidopropyl betaines,and alkyl sultaines, such as cocodimethyl sulfopropyl betaine,stearyldimethyl sulfopropyl betaine, lauryl dimethyl sulfoethyl betaine,lauryl bis-(2-hydroxy-ethyl)sulfopropyl betaine andalkylamidopropylhydroxy sultaines.

In one embodiment, the personal care composition further comprises anelectrolyte, typically in an amount of up to about 20 pbw per 100 pbw ofthe personal care composition. Suitable electrolytes are known compoundsand include salts of multivalent anions, such as potassiumpyrophosphate, potassium tripolyphosphate, and sodium or potassiumcitrate, salts of multivalent cations, including alkaline earth metalsalts such as calcium chloride and calcium bromide, as well as zinchalides, barium chloride and calcium nitrate, salts of monovalentcations with monovalent anions, including alkali metal or ammoniumhalides, such as potassium chloride, sodium chloride, potassium iodide,sodium bromide, and ammonium bromide, alkali metal or ammonium nitrates,and polyelectrolytes, such as uncapped polyacrylates, polymaleates, orpolycarboxylates, lignin sulfonates or naphthalene sulfonateformaldehyde copolymers.

In one embodiment, the personal care composition comprises water, ananionic surfactant, a structuring agent for the anionic surfactant, anda pH responsive polymer according to the present invention and exhibitsone or more lamellar surfactant phases. “Lamellar surfactant phases” arephases which comprise one or more surfactant bilayers, typically aplurality of surfactant bilayers separated by liquid medium. Lamellarphases include spherulite phases and the typical form of the liquidcrystal G-phase, as well as mixtures thereof. “G-phases”, which aresometimes referred to in the literature as “L, phases”, are typicallypourable, non-Newtonian, anisotropic products that are cloudy lookingand exhibit a characteristic “smeary” appearance on flowing. Lamellarphases can exist in several different forms, including domains ofparallel sheets, which constitute the bulk of the typical G-phasesdescribed above and spherulites formed from a number of concentricspherical shells, each of which is a bilayer of surfactant. In thisspecification the term “G-phase” will be reserved for compositions,which are at least partly of the former type. The spherulites aretypically between 0.1 and 50 microns in diameter and so differfundamentally from micelles. The surfactant phase morphology of thestructured surfactant composition is observed, for example, using anoptical microscope under cross-polarized light at about 40×magnification.

In one embodiment, the personal care composition of the presentinvention exhibits structured surfactant properties, that is,shear-thinning viscosity and a capacity to suspend water insoluble orpartially water soluble components.

As used herein in reference to viscosity, the terminology“shear-thinning” means that such viscosity decreases with an increase inshear rate. Shear-thinning may be characterized as a “non-Newtonian”behavior, in that it differs from that of a classical Newtonian fluid,for example, water, in which viscosity is not dependent on shear rate.

As used herein in reference to a component of an aqueous composition,the terminology “water insoluble or partially water soluble components”means that the component is present in the aqueous composition at aconcentration above the solubility limit of the component so that, inthe case of a water insoluble component, the component remainssubstantially non-dissolved in the aqueous composition and, in the caseof a partially water soluble component, at least a portion of suchcomponent remains undissolved in the aqueous composition.

As used herein, characterization of an aqueous composition as “capableof suspending”, or as being “able of suspend” water insoluble orpartially water insoluble components means that the compositionsubstantially resists flotation of such components in the composition orsinking of such components in such composition so that such componentsappear to be neutrally buoyant in such composition and remain at leastsubstantially suspended in such composition under the anticipatedprocessing, storage, and use conditions for such aqueous composition.

In one embodiment, the personal care composition of the presentinvention comprises, based on 100 pbw of the composition from about 5 toabout 40 parts pbw, more typically from about 10 to about 30 pbw, andstill more typically from about 15 to about 25 pbw, of the anionicsurfactant and from about 0.1 to about 25 pbw, more typically, fromabout 0.5 to about 10 pbw, of a structuring agent.

In one embodiment, the pH of the lamellar phase containing personal carecomposition is from about 5.0 to about 7.0, more typically from about5.5 to about 6.5.

Suitable anionic surfactants include those described above. In oneembodiment of the lamellar phase containing personal care composition,the anionic surfactant comprises one or more branched and/or unsaturatedanionic surfactants. Suitable branched anionic surfactants include, forexample, sodium trideceth sulfate, sodium tridecyl sulfate, ammoniumtrideceth sulfate, and ammonium tridecyl sulfate.

Suitable structuring agents include cationic surfactants, amphotericsurfactants, fatty alcohols, alkoxylated alcohols, fatty acids, fattyacid esters, alkanolamides, amine oxides, and electrolytes, and mixturesthereof. An effective amount of such structuring agent is one thatpromotes and/or does not interfere with the formation of a lamellarsurfactant phase. Suitable cationic surfactants, amphoteric surfactants,fatty alcohols, alkoxylated alcohols, fatty acids, fatty acid esters,alkanolamides, amine oxides, and electrolytes are described above.

Typically, the greater the amount of surfactant present in relation toits solubility, the smaller the amount electrolyte that may be requiredin order to form a structure capable of supporting solid materialsand/or to cause flocculation of the structured surfactant. In oneembodiment, the composition contains a sufficient amount of anelectrolyte to promote formation lamellar surfactant phases.

In one embodiment, the personal care composition of the presentinvention further comprises, typically in an amount of from greater than0 pbw to about 50 pbw, more typically form about 1 to about 30 pbw, per100 pbw of the personal care composition, one or more “benefit agents”that is, materials that provide a personal care benefit, such asmoisturizing or conditioning, to the user of the personal carecomposition, such as, for example, emollients, moisturizers,conditioners, polymers, vitamins, abrasives, UV absorbers, antimicrobialagents, anti-dandruff agents, fragrances, and/or appearance modifyingadditives, such as, for example, colored particles or reflectiveparticles, which may be in the form of a solid, liquid, or gas and maybe insoluble or are only partly soluble in the personal carecomposition. Mixtures of the benefit agents may be used.

In one embodiment, the personal care composition is a hair stylingcomposition. Suitable hair styling compositions may be in the form of agel, mousse, or spray and may be applied to the hair and/or skin, forexample, by hand or by spraying, as appropriate in view of the form ofthe composition.

In one embodiment, the personal care composition is a hair styling gelthat comprises a hair styling polymer, a pH responsive polymer of thepresent invention, and a carrier, such as water, a (C2-C6)alkanol, or amixture thereof.

Suitable hair styling polymers typically comprise multiple cationicsites per molecule and include, for example, polyquaternium-11,polyquaternium4, polyquaternium-7, polyquaternium-16, polyquaternium-28,polyquaternium-44, polyquaternium-46, polyquaternium-55,polyquaternium-68 and polyquaternium-88. Suitable hair styling polymersalso include, but are not limited to copolymers of polyvinylpyrrolidone,vinyl acetate, polyvinylcaprolactam, methylether maleic acid,acrylamides, octylacrylamide, butylaminoethyl, crotonic acid,dimethylaminopropyl methacrylate and dimethylaminoethyl methacrylate,and mixtures thereof.

As used herein, the term “mousse” means a composition that is in theform of a foam when applied. In one embodiment, the personal carecomposition is a hair styling mousse is packaged in a pressurizedcontainer and comprises a hair styling polymer, a pH responsive polymerof the present invention, a carrier, such as water, a (C2-C6)alkanol, apropellant suitable for foaming the composition when the composition isdispensed from the container. Suitable propellants are liquefiablegases, such as, for example, propane, butane, isobutane, nitrogen,carbon dioxide, nitrous oxide, 1,2-difluoroethane.

In one embodiment, the personal care composition is a hair spraycomposition suitable for spray application from a container that isequipped with a mechanical sprayer, comprising a hair styling polymer, apH responsive polymer of the present invention, and a carrier, such aswater, a (C2-C6)alkanol, or a mixture thereof.

In one embodiment, the personal care composition is an aerosol hairspray composition suitable for spray application from a pressurizedcontainer and comprises, a hair styling polymer, a carrier, typically a(C1-C6)alkanol or a (C7-C10) isoparaffin, a pH responsive polymer of thepresent invention, and a propellant suitable for aerosol delivery of thehair spray composition to the hair. Suitable propellants are thosedescribed above in regard to the hair styling mousse embodiment of thepersonal care composition of the present invention.

The hair styling gel, mousse, and hair spray may in each case,optionally further comprise one or more emollients, conditioning agents,shine enhancers, moisture and heat sensitive moieties, or a mixturethereof. Suitable emollients include, for example, PEG-40 castor oil,glycerol, propylene glycol, butylene glycol. Suitable conditioning andshine agents include, for example, quaternized and/or hydrolyzedproteins of honey, soy, wheat, guar or maize, cetyl alcohol, stearylalcohol, ceteareth-20, isopropyl palmitate, cyclopentasiloxane,cyclomethicone, trimethylsilyamodimethicone, phenyltrimethicone,ethoxylated/propylated dimethicone, dimethiconol, panthenol, tocopherolacetate, tocopherol, cetrimmonium chloride, hair keratin and silk aminoacids and ethoxylated/propoxylated waxes of fruit and vegetable origin.

The personal care composition according to the present invention mayoptionally further comprise one or more adjuvants, such as, for example,preservatives such as benzyl alcohol, methyl paraben, propyl paraben andimidazolidinyl urea; pH adjusting agents such as citric acid, succinicacid, phosphoric acid, sodium hydroxide, sodium carbonate; dyes, andsequestering agents such as disodium ethylenediamine tetra-acetate.

In general, personal care compositions may optionally comprise, based on100 pbw of the personal care composition and independently for each suchadjuvant, from about 0 to about 10 pbw, typically from 0.5 pbw to about5.0 pbw, of such optional adjuvants, depending on the desired propertiesof the personal care composition.

The pH responsive polymer of the present application is useful as acomponent in aqueous fluid compositions used in oilfield applications.

In one embodiment, an aqueous fluid composition of the present inventioncomprises water and a pH responsive polymer of the present invention,typically from about 0.05 to about 40 pbw, more typically 0.1 pbw to 20pbw, even more typically form about 1 to about 10 pbw of the pHresponsive polymer per 100 pbw composition, wherein the pH of thecomposition is greater than or equal to about 6, more typically, fromabout 6 to about 10.

X. Use with Materials in Geological Formations

A. Fracturing Fluids

In one embodiment, the aqueous fluid composition of the presentinvention is used as the fracturing fluid in a method for hydraulicfracturing of a geologic formation to stimulate the production offluids, such as oil and/or natural gas, from the formation. Thefracturing fluid is injected through a wellbore and against a surface ofthe formation at a pressure and flow rate at least sufficient toinitiate and/or extend one or more fractures in the formation.Typically, the fracturing fluid further comprises a proppant dispersedin the fracturing fluid. Suitable proppants are inorganic particles,such as sand, bauxite particles, or glass beads and are typically in therange of from about 20 to about 40 mesh. Such fracturing fluidcompositions typically contain, based on 100 pbw of the liquid componentof such composition, from about 90 pbw to about 100 pbw water, fromabout 0.1 pbw to about 10 pbw pH responsive polymer, and from about 10pbw to about 150 pbw proppant. The proppant particles are transportedinto fractures in the geologic formation by the pressurized fracturingfluid stream and keep the fractures from closing back down when thestream of fracturing fluid is discontinued. The proppant-filledfractures provide permeable channels through which the formation fluidscan flow to the wellbore and then be withdrawn. Hydraulic fracturingfluids are subject to high temperatures and shear rates.

The polymer and composition of the present invention may be used in thefracturing fluid in an amount of from 0.01 to 5% by weight of the fluid.

A.1. Crosslinking Agent

A crosslinking agent may be used with the fracturing fluids. Thecrosslinking agents used may include aluminum or antimony or Group 4transition metal compound crosslinking agents. The crosslinking agentmay include zirconium, titanium and hafnium crosslinking agents, andcombinations of these, and may include organo-metallic compounds.Examples of suitable zirconium crosslinking agents include zirconiumtriethanolamine, L-glutamic acid-triethanolamine-zirconium, zirconiumdiethanolamine, zirconium tripropanolamine, and zirconium lactatecomplexes, and/or the related salts, and/or their mixtures. Examples oftitanium crosslinking agents include titanium triethanolamine,dihydroxybis(ammonium lactato)titanium, and titanium acetylacetonate.The crosslinking agent may be included in the fluid in an amount of fromabout 0.01% to about 1.5% by weight of the fluid, more particularly,from about 0.02% to about 0.3% by weight of the fluid.

A.2. Buffering Agent

A hydroxyl ion releasing agent or buffering agent may be employed toadjust the pH or buffer the fluid, i.e., moderate amounts of either astrong base or acid may be added without causing any large change in pHvalue of the fluid. These may useful in changing the rate ofcrosslinking. Alkaline amine or polyamine compounds useful to raise thepH to the desirable level are outlined in U.S. Pat. No. 4,579,670, andinclude tetramethylenediamine, triethylenetetramine,tetraethylenepentamine (TEPA), diethylenetriamine, triethylenediamine,triethylenepentamine, ethylenediamen and similar compounds. The alkalimetal hydroxides, e.g., sodium hydroxide, and carbonates can also beused. Other acceptable materials are Ca(OH)₂, Mg(OH)₂, Bi(OH)₃, Co(OH)₂,Pb(OH)₂, Ni(OH)₂, Ba(OH)₂, and Sr(OH)₂. Acids such as hydrochloric acid,sulfuric acid, nitric acid, citric acid, acetic acid, fumaric acid,maleic acid, can be used to lower the pH.

In various embodiments, the buffering agent is a combination of a weakacid and a salt of the weak acid; an acid salt with a normal salt; ortwo acid salts. Examples of suitable buffering agents are acetic acid-Naacetate; NaH₂PO₄—Na₂PO₄; sodium carbonate-sodium bicarbonate; and sodiumbicarbonate, or other like agents. By employing a buffering agentinstead of merely a hydroxyl ion producing material, a fluid is providedwhich is more stable to a wide range of pH values found in local watersupplies and to the influence of acidic materials located in formationsand the like.

A.3. Gas Component

The fracturing fluids may contain a gas component, as discussed above.The gas component may be provided from any suitable gas that forms anenergized fluid or foam when introduced into the aqueous medium. See,for example, U.S. Pat. No. 3,937,283 (Blauer et al.), hereinafterincorporated by reference. The gas component may comprise a gas selectedfrom nitrogen, air, argon, carbon dioxide, and any mixtures thereof.Particularly useful are the gas components of nitrogen or carbondioxide, in any quality readily available. The gas component may assistin the fracturing, and also the capacity of the fluid to carry solids,such as proppants. The presence of the gas also enhances the flowback ofthe fluid to facilitate cleanup. The fluid may contain from about 10% toabout 90% volume gas component based upon total fluid volume percent,more particularly from about 20% to about 80% volume gas component basedupon total fluid volume percent, and more particularly from about 30% toabout 70% volume gas component based upon total fluid volume percent.

A.4. Breaker

Fracturing fluids based on the invention may also comprise a breaker.The purpose of this component is to “break” or diminish the viscosity ofthe fluid so that this fluid is more easily recovered from the formationduring cleanup. With regard to breaking down viscosity, oxidizers,enzymes, or acids may be used. Breakers reduce the polymers molecularweight by the action of an acid, an oxidizer, an enzyme, or somecombination of these on the polymer itself. The breakers may includepersulfates such as ammonium persulfate, sodium persulfate, andpotassium persulfate, bromates such as sodium bromate and potassiumbromate, periodates, metal peroxides such as calcium peroxide,chlorites, and the like, and the combinations of these breakers, live orencapsulated.

A.5. Proppant

Embodiments of the invention used as fracturing fluids may also includeproppant particles substantially insoluble in the fluids of theformation. Proppant particles carried by the treatment fluid remain inthe fracture created, thus propping open the fracture when thefracturing pressure is released and the well is put into production.Suitable proppant materials include, but are not limited to, sand,walnut shells, sintered bauxite, glass beads, ceramic materials,naturally occurring materials, or similar materials. Mixtures ofproppants can be used as well. If sand is used, it will typically befrom about 20 mesh (0.841 mm) to about 100 mesh (0.0059 mm) in size.With synthetic proppants, mesh sizes of about 8 (0.937 mm) or greatermay be used. Naturally occurring materials may be underived and/orunprocessed naturally occurring materials, as well as materials based onnaturally occurring materials that have been processed and/or derived.Suitable examples of naturally occurring particulate materials for useas proppants include, but are not necessarily limited to: ground orcrushed shells of nuts such as walnut, coconut, pecan, almond, ivorynut, brazil nut, etc.; ground or crushed seed shells (including fruitpits) of seeds of fruits such as plum, olive, peach, cherry, apricot,etc.; ground or crushed seed shells of other plants such as maize (e.g.,corn cobs or corn kernels), etc.; processed wood materials such as thosederived from woods such as oak, hickory, walnut, poplar, mahogany, etc.including such woods that have been processed by grinding, chipping, orother form of particalization, processing, etc. Further information onnuts and composition thereof may be found in Encyclopedia of ChemicalTechnology, Edited by Raymond E. Kirk and Donald F. Othmer, ThirdEdition, John Wiley & Sons, Volume 16, pages 248-273 (entitled “Nuts”),Copyright 1981, which is incorporated herein by reference.

The concentration of proppant in the fluid can be any concentrationknown in the art, and will preferably be in the range of from about 0.03to about 3 kilograms of proppant added per liter of liquid phase. Also,any of the proppant particles can further be coated with a resin topotentially improve the strength, clustering ability, and flow backproperties of the proppant.

A.6. Aqueous Media

The aqueous medium of the fracturing fluids of the present invention maybe water or brine. In those embodiments of the invention where theaqueous medium is a brine, the brine is water comprising an inorganicsalt or organic salt. Inorganic salts may include alkali metal halides,such as potassium chloride. The carrier brine phase may also comprise anorganic salt, such as sodium or potassium formate. Inorganic divalentsalts include calcium halides, such as calcium chloride or calciumbromide. Sodium bromide, potassium bromide, or cesium bromide may alsobe used. The salt may be chosen for compatibility reasons i.e. where thereservoir drilling fluid used a particular brine phase and thecompletion/clean up fluid brine phase is chosen to have the same brinephase. Typical salt levels are 2 to 30 wt % salt based on overallcomposition of the aqueous brine. The most common level of salt in brineis 2-10 weight % sodium chloride, potassium chloride or mixtures thereofbased on overall composition of the aqueous brine.

A.7. Fiber Component

A fiber component may be included in the fracturing fluids of theinvention to achieve a variety of properties including improvingparticle suspension, and particle transport capabilities, and gas phasestability. Fibers used may be hydrophilic or hydrophobic in nature, buthydrophilic fibers may be useful for some applications. Fibers can beany fibrous material, such as, but not necessarily limited to, naturalorganic fibers, comminuted plant materials, synthetic polymer fibers (bynon-limiting example polyester, polyaramide, polyamide, novoloid or anovoloid-type polymer), fibrillated synthetic organic fibers, ceramicfibers, inorganic fibers, metal fibers, metal filaments, carbon fibers,glass fibers, ceramic fibers, natural polymer fibers, and any mixturesthereof. Particularly useful fibers are polyester fibers coated to behighly hydrophilic, such as, but not limited to, DACRON polyethyleneterephthalate (PET) fibers available from Invista Corp. Wichita, Kans.,USA, 67220. Other examples of useful fibers include, but are not limitedto, polylactic acid polyester fibers, polyglycolic acid polyesterfibers, polyvinyl alcohol fibers, and the like. When used in fluids ofthe invention, the fiber component may be include at concentrations fromabout 1 to about 15 grams per liter of the liquid phase of the fluid, incertain applications the concentration of fibers may be from about 2 toabout 12 grams per liter of liquid, and in others from about 2 to about10 grams per liter of liquid.

A.8. Other Optional Ingredients

Fluid embodiments of fracturing fluids of the invention may furthercontain other additives and chemicals known to be commonly used inoilfield applications by those skilled in the art. These include, butare not necessarily limited to, materials such as surfactants inaddition to those mentioned herein, clay stabilizers such as tetramethylammonium chloride and/or potassium chloride, breaker aids in addition tothose mentioned herein, oxygen scavengers, alcohols, scale inhibitors,corrosion inhibitors, fluid-loss additives, bactericides, and the like.Also, they may include a co-surfactant to optimize viscosity or tominimize the formation of stable emulsions that contain components ofcrude oil or a polysaccharide or chemically modified polysaccharide,polymers such as cellulose, derivatized cellulose, guar gum, derivatizedguar gum, xanthan gum, or synthetic polymers such as polyacrylamides andpolyacrylamide copolymers, oxidizers such as ammonium persulfate andsodium bromate, and biocides such as 2,2-dibromo-3-nitrilopropionamine.The fluid should be substantially devoid of hectorite clay or other claycomponents and such components may be present in the fluid only inamounts of less than 0.1% by weight.

Aqueous fluid embodiments of the invention may also comprise anorganoamino compound. Examples of suitable organoamino compoundsinclude, but are not necessarily limited to, tetraethylenepentamine(TEPA), triethylenetetramine, pentaethylenehexamine, triethanolamine,and the like, or any mixtures thereof. When organoamino compounds areused in fluids of the invention, they are incorporated at an amount fromabout 0.01 wt % to about 2.0 wt % based on total liquid phase weight.The organoamino compound may be incorporated in an amount from about0.05 wt % to about 1.0 wt % based on total weight of the fluid. Aparticularly useful organoamino compound is tetraethylenepentamine(TEPA).

A.9. Hydraulic Fracturing Techniques

The fluids of the invention may be used for hydraulically fracturing asubterranean formation. Techniques for hydraulically fracturing asubterranean formation are known to persons of ordinary skill in theart, and involve pumping the fracturing fluid into the borehole and outinto the surrounding formation. The fluid pressure is above the minimumin situ rock stress, thus creating or extending fractures in theformation. See Stimulation Engineering Handbook, John W. Ely, PennwellPublishing Co., Tulsa, Okla. (1994), U.S. Pat. No. 5,551,516 (Normal etal.), “Oilfield Applications”, Encyclopedia of Polymer Science andEngineering, vol. 10, pp. 328-366 (John Wiley & Sons, Inc. New York,N.Y., 1987) and references cited therein, the disclosures of which areincorporated herein by reference thereto.

In the fracturing treatment, fluids of the present invention may be usedin the pad treatment, the proppant stages, or both. The components ofthe liquid phase may be mixed on the surface. Alternatively, the fluidmay be prepared on the surface and pumped down tubing while any gascomponent could be pumped down the annulus to mix down hole, or viceversa.

In hydraulic fracturing the fracturing fluid comprising water solublepolymer and at least one nonionic surfactant is pumped into the targetedformation at a rate in excess of what can be dissipated through thenatural permeability of the formation rock. The fracturing fluids resultin a pressure build up until such pressure exceeds the strength of theformation rock. When this occurs, the formation rock fails and aso-called “fracture” is initiated. With continued pumping, the fracturegrows in length, width and height.

At a predetermined time in the pumping process, solid particulate istypically added to the fluid that is being pumped. This particulate iscarried down the well, out of the wellbore and deposited in the createdfracture. It is the purpose of this specially designed particulate tokeep the fracture from “healing” to its initial position (after pumpinghas ceased). The particulate is said to be propping open the fractureand is therefore designated as “proppant”. The fracture, which isgenerated by the application of this stimulation technique, creates aconductive path to the wellbore for the hydrocarbon.

Typical proppant is selected from the group consisting of gravel, quartzsand grains, sintered bauxite, glass and ceramic beads, walnut shellfragments, or aluminum pellets. The fracturing fluid may also include athermal stabilizer, for example sodium thiosulfate, methanol, ethyleneglycol, isopropanol, thiourea, and/or sodium thiosulfite. The fracturingfluid may also include KCl as a clay stabilizer.

B. Acidizing

Producing oil and gas wells have long been treated to stimulateproduction thereof utilizing a method termed “acidizing” in which anemulsion of an aqueous mineral acid either alone or in combination withvarious surfactants, corrosion inhibiting agents, and hydrocarbon oilsis added to a producer well. Presumably, such treatments tend to removedeposits from the area of the subterranean oil or gas formationimmediately adjacent to the production well bore, thus increasing thepermeability of the formation and allowing residual oil or gas to berecovered through the well bore. Another object of such “acidizing”treatment of oil or gas producer wells is the removal of water from theinterstices of the formation by the use of a composition whichmaterially lowers the interfacial forces between the water and the oilor gas. Various surface-active agents have been recommended for thisuse.

Producing oil and gas wells have long been treated to stimulateproduction thereof utilizing a method termed “acidizing” in which anemulsion of an aqueous mineral acid either alone or in combination withvarious surfactants, corrosion inhibiting agents, and hydrocarbon oilsis added to a producer well. Presumably, such treatments tend to removedeposits from the area of the subterranean oil or gas formationimmediately adjacent to the production well bore, thus increasing thepermeability of the formation and allowing residual oil or gas to berecovered through the well bore. Another object of such “acidizing”treatment of oil or gas producer wells is the removal of water from theinterstices of the formation by the use of a composition whichmaterially lowers the interfacial forces between the water and the oilor gas. Various surface-active agents have been recommended for thisuse.

Acidizing, and fracturing procedures using acidic treatment fluids, arecommonly carried out in subterranean well formations to accomplish anumber of purposes including, but not limited to, to facilitate therecovery of desirable hydrocarbons from the formation. As used herein,the term “treatment fluid” refers to any fluid that may be used in asubterranean application in conjunction with a desired function and/orfor a desired purpose. The term “treatment fluid” does not imply anyparticular action by the fluid or any component thereof.

One commonly used aqueous acidic treatment fluid comprises hydrochloricacid. Other commonly used acids for acidic treatment fluids includehydrofluoric acid, acetic acid, formic acid, citric acid, ethylenediamine tetra acetic acid (“EDTA”), glycolic acid, sulfamic acid, andderivatives or combinations thereof.

Acidic treatment fluids are used in various subterranean operations. Forexample, formation acidizing or “acidizing” is a method for, among otherpurposes, increasing the flow of desirable hydrocarbons from asubterranean formation. In a matrix acidizing procedure, an aqueousacidic treatment fluid is introduced into a subterranean formation via awell bore therein under pressure so that the acidic treatment fluidflows into the pore spaces of the formation and reacts with (e.g.,dissolves) the acid-soluble materials therein. As a result, the porespaces of that portion of the formation are enlarged, and thepermeability of the formation may increase. The flow of hydrocarbonsfrom the formation therefore may be increased because of the increase information conductivity caused, inter alia, by dissolution of theformation material. In fracture acidizing procedures, one or morefractures are produced in the formation(s) and an acidic treatment fluidis introduced into the fracture(s) to etch flow channels therein. Acidictreatment fluids also may be used to clean out well bores to facilitatethe flow of desirable hydrocarbons. Other acidic treatment fluids may beused in diversion processes and well bore clean-out processes. Aspecific example is filter cake removal.

To increase the viscosity of an aqueous acidic treatment fluid, asuitable gelling agent may be included in the treatment fluid (oftenreferred to as “gelling” the fluid). Gelling an aqueous acidic treatmentfluid may be useful, among other purposes, to prevent the acid frombecoming prematurely spent and inactive. Additionally, gelling anaqueous acidic treatment fluid may enable the development of widerfractures so that the gelled acidic treatment fluid may delay theinteraction of the acid with an acid soluble component in the well boreor the formation. Moreover, gelling an aqueous acidic treatment fluidmay permit better fluid loss control.

Acidic treatment fluids used in subterranean operations arepredominantly water-based fluids that comprise gelling agents toincrease their viscosities. Common gelling agents includepolysaccharides (such as xanthan), synthetic polymers (such aspolyacrylamide), and surfactant gel systems. To assist the gellingagents in maintaining these viscosities in the presence of the hightemperatures and slat concentrations experienced downhole thecomposition includes the polymer combinations of the present invention.

The aqueous base fluids of the acidic treatment fluids of the presentinvention generally comprise fresh water, salt water, sea water, a brine(e.g., a saturated salt water or formation brine), or a combinationthereof. Other water sources may be used, including those comprisingmonovalent, divalent, or trivalent cations (e.g., magnesium, calcium,zinc, or iron) and, where used, may be of any weight. If a water sourceis used that contains such divalent or trivalent cations inconcentrations sufficiently high to be problematic, then such divalentor trivalent salts may be removed, either by a process such as reverseosmosis, or by raising the pH of the water in order to precipitate outsuch divalent salts to lower the concentration of such salts in thewater before the water is used. Another method would be to include achelating agent to chemically bind the problematic ions to prevent theirundesirable interactions with the clarified xanthan. Suitable chelantsinclude, but are not limited to, citric acid or sodium citrate, ethylenediamine tetra acetic acid (“EDTA”), hydroxyethyl ethylenediaminetriacetic acid (“HEDTA”), dicarboxymethyl glutamic acid tetrasodium salt(“GLDA”), diethylenetriaminepentaacetic acid (“DTPA”),propylenediaminetetraacetic acid (“PDTA”),ethylenediaminedi(o-hydroxyphenylacetic) acid (“EDDHA”), glucoheptonicacid, gluconic acid, and the like, and nitrilotriacetic acid (“NTA”).Other chelating agents also may be suitable. One skilled in the art willreadily recognize that an aqueous base fluid containing a high level ofmulti-valent ions should be tested for compatibility prior to use.

The gelling agents comprising the polymers of the present invention maybe present in an acidic treatment fluid of the present invention in anamount of from about 1 lb/Mgal to about 200 lb/Mgal. In embodimentswherein the gelling agents comprising clarified xanthan further comprisescleroglucan, one may include about 1 lb/Mgal to about 200 lb/Mgal ofscleroglucan. In an acidic treatment fluid that comprises hydrochloricacid, one may include about 1 to about 200 lb/Mgal of scleroglucan. Inembodiments wherein the gelling agents comprising clarified xanthanfurther comprise diutan, one may include about 1 to about 200 lb/Mgal ofdiutan. In an acidic treatment fluid that comprises about 15%hydrochloric acid, one may include about 1 to about 200 lb/Mgal ofdiutan. In some embodiments, one may include about 10 to about 150lb/Mgal of clarified xanthan, scleroglucan, and/or diutan. A person ofskill in the art with the benefit of this disclosure will recognize thatany specific concentration or narrower range of concentrations of thegelling agents of the present invention encompassed by the broaderconcentration ranges specifically articulated above may be used and/ormay be particularly advantageous for a particular embodiment of thepresent invention.

In certain embodiments, the acidic treatment fluids of the presentinvention also may comprise any additional additive that may be suitablein a particular application of the present invention, including, but notlimited to, any of the following: hydrate inhibitors, clay stabilizers,bactericides, salt substitutes (such as tetramethyl ammonium chloride),relative permeability modifiers (such as HPT-1.™. chemical additiveavailable from Halliburton Energy Services, Duncan, Okla.), sulfidescavengers, fibers, nanoparticles, consolidating agents (such as resinsand/or tackifiers), corrosion inhibitors, corrosion inhibitorintensifiers, pH control additives, surfactants, breakers, fluid losscontrol additives, scale inhibitors, asphaltene inhibitors, paraffininhibitors, salts, bactericides, crosslinkers, stabilizers, chelants,foamers, defoamers, emulsifiers, demulsifiers, iron control agents,solvents, mutual solvents, particulate diverters, gas phase, carbondioxide, nitrogen, other biopolymers, synthetic polymers, frictionreducers, combinations thereof, or the like. The acidic treatment fluidsof the present invention also may include other additives that may besuitable for a given application, as will be recognized by a person ofordinary skill in the art, with the benefit of this disclosure.

While typically not required, the acidic treatment fluids of the presentinvention also may comprise breakers capable of reducing the viscosityof the acidic treatment fluid at a desired time. Examples of suchbreakers that may be suitable for the acidic treatment fluids of thepresent invention include, but are not limited to, sodium chlorite,hypochlorites, perborates, persulfates, peroxides (including organicperoxides), enzymes, derivatives thereof, and combinations thereof.Other suitable breakers may include suitable acids. Examples ofperoxides that may be suitable include tert-butyl hydroperoxide andtert-amyl hydroperoxide. A breaker may be included in an acidictreatment fluid of the present invention in an amount and formsufficient to achieve the desired viscosity reduction at a desired time.The breaker may be formulated to provide a delayed break, if desired.For example, a suitable breaker may be encapsulated if desired. Suitableencapsulation methods are known to those skilled in the art. Onesuitable encapsulation method that may be used involves coating thebreaker(s) with a material that will degrade when placed downhole so asto release the breaker at the appropriate time. Coating materials thatmay be suitable include, but are not limited to, polymeric materialsthat will degrade when downhole. The terms “degrade,” “degradation,” or“degradable” refer to both the two relatively extreme cases ofhydrolytic degradation that the degradable material may undergo, i.e.,heterogeneous (or bulk erosion) and homogeneous (or surface erosion),and any stage of degradation in between these two. This degradation canbe a result of, inter alia, a chemical or thermal reaction or a reactioninduced by radiation. Suitable examples of materials that can undergosuch degradation include polysaccharides such as dextran or cellulose;chitins; chitosans; proteins; aliphatic polyesters; poly(lactides);poly(glycolides); poly(.epsilon.-caprolactones), poly(hydroxybutyrates);poly(anhydrides); aliphatic polycarbonates; orthoesters,poly(orthoesters); poly(amino acids); poly(ethylene oxides);polyphosphazenes; derivatives thereof; and combinations thereof. Ifused, a breaker should be included in a composition of the presentinvention in an amount sufficient to facilitate the desired reduction inviscosity in a viscosified treatment fluid. For instance, peroxideconcentrations that may be used vary from about 0.1 to about 10 gallonsof peroxide per 1000 gallons of the acidic treatment fluid.

C. Enhanced Oil Recovery

The present invention may be employed with other techniques to furtherimprove hydrocarbon recovery from subterranean formations. Initially,oil is produced from the fractured formation by pressure depletion(primary recovery). In this method, the differential pressure betweenthe formation and a production well or wells forces the oil containedwithin the formation toward a production well where it can be recovered.Traditionally secondary recovery processes through injection of water orgas are used to displace additional oil toward producing wells.Typically, up to about 35 percent of the oil which is initiallycontained in a formation can be recovered in average through primary andsecondary recovery. This leaves a large quantity of oil within theformation. Additionally, some formations contain oil which is tooviscous to be efficiently recovered from the formation using primary andsecondary processes. Because of the need to recover a larger percentageof the oil from a formation, methods have been developed to recover oilwhich could not be recovered using only pressure depletion techniques.These methods are typically referred to as “enhanced oil recoverytechniques” (EOR).

Thus, the present invention is also directed to a method for recoveringcrude oil from a subterranean formation, comprising introducing to theformation an aqueous medium comprising water or brine and thecomposition of the present invention including a combination of anionicpolymer and cationic polymer described above.

The global average recovery factor for conventional oil fields is about35% and it could be raised up to 50% through enhanced oil recovery.There are two essentials components to EOR: improving displacementefficiency and improving macroscopic sweep efficiency. The presentinvention enhances oil recovery by maintaining stable viscosity at hightemperatures. The method of the invention is particularly useful in thestimulation of oil and gas wells which have failed to respond toacidizing treatment of the producing well including the use of variousacids with various surfactants.

C.1. Chemical Flooding

A promising EOR method is an enhanced oil recovery process referred toas chemical flooding which generally covers the use of polymer and/orsurfactant slugs. In polymer flooding, a polymer solution is injected todisplace oil toward producing wells. The polymer solution is designed todevelop a favorable mobility ratio between the injected polymer solutionand the oil/water bank being displaced ahead of the polymer. However,the use of polymer is not always satisfactory as many polymer solutionsare sensitive to brine type and concentration which can affect theapparent viscosity of the solution. In surfactant flooding, an aqueoussolution containing surfactant is injected into the oil rich formation.Residual oil drops are deformed as a result of low Interfacial Tensionprovided by surfactant solution and drops are displaced through the porethroats and displaced oil is the recovered. See U.S. Pat. No. 7,789,160to Hough et al. incorporated herein by reference in its entirety.

The present compositions advantageously are compatible with anionicsurfactants typically used to decrease interfacial tension to alsoassist in enhancing oil recovery from subterranean formations.

The present invention proves enhanced oil recovery. For example, thepresent invention is also directed to a method for recovering crude oilfrom a subterranean formation, comprising introducing to the formationan aqueous medium comprising water or brine and the composition of thepresent invention including a combination of polyanionic polymer andpolycationic polymer described above.

There are two important components to EOR: improving displacementefficiency and improving macroscopic sweep efficiency. The presentinvention enhances oil recovery by maintaining stable viscosity at hightemperatures. The method of the invention is particularly useful in thestimulation of oil and gas wells which have failed to respond toacidizing treatment of the producing well including the use of variousacids with various surfactants.

The present compositions advantageously are compatible with anionicsurfactants typically used to decrease interfacial tension to alsoassist in enhancing oil recovery from subterranean formations.

The aqueous medium of the composition may be soft water, brackish wateror brine. Typically the aqueous medium in compositions used to treatsubterranean formations comprises brine.

C.2. Other Ingredients

Compositions of the invention may contain components in addition towater, the first cationic or cationaizable polymer, the second anionicor anionizable polymer and optional surfactants. Such additionalcomponents are, for example, co-solvents, acids, bases, buffers,chelating agents for the control of multivalent cations, freezing pointdepressants, etc.

For example, a hydrocarbon recovery composition according to the presentinvention may be provided to the hydrocarbon containing formation aloneor with other compounds for enhancing oil recovery. For example, theseother compounds may be other nonionic additives (e.g., alcohols,ethoxylated alcohols and/or sugar based esters). Some embodiments haveless than 0.3 weight percent of one or more anionic surfactants (e.g.sulfates, sulfonates, ethoxylated sulfates, and/or phosphates). In someembodiments the composition has less than 0.3 wt % each of anionicsurfactant, amphoteric surfactant and zwitterionic surfactant. Ifdesired, there may be an absence of anionic surfactant, an absence ofamphoteric surfactant, and an absence of zwitterionic surfactant.

C.3. Alcohol

Alcohol can be used as mutual solvent to reduce water saturation. Theinterfacial tension between oil and ethanol is much lower than betweenoil and brine.

Capillary forces of retention for the alcohol are much reduced comparedto those for brine.

It has been reported that isopropyl or butyl alcohol plus methyl alcoholcould be used in miscible displacement to increase oil recovery ofnaphtha and mineral oil.

Others have investigated enhanced oil recovery by alcohol flooding.Their process design was strongly guided by the ternary phase ofalcohol/oil/brine. They showed that oil recovery was highly dependent onthe choice of alcohol/oil/brine combinations. Others have reported thatinjection of appropriate combinations of oil-soluble and water-solublesolvents such as alcohols and ketones could significantly enhance oilrecovery.

In an embodiment, an aliphatic nonionic additive may be used in ahydrocarbon recovery composition. As used herein, the term “aliphatic”refers to a straight or branched chain of carbon and hydrogen atoms. Insome embodiments, an aliphatic portion of an aliphatic nonionic additivemay have an average carbon number from 10 to 24. In some embodiments, analiphatic portion of an aliphatic nonionic additive may have an averagecarbon number from 12 to 18. In some embodiments, the aliphatic nonionicadditive may include a branched aliphatic portion. A branched aliphaticportion of an aliphatic nonionic additive may have an average carbonnumber from 16 to 17. In some embodiments, a branched aliphatic group ofan aliphatic nonionic additive may have less than about 0.5 percentaliphatic quaternary carbon atoms. In an embodiment, an average numberof branches per aliphatic nonionic additive ranges from about 0.1 toabout 2.5. In other embodiments, an average number of branches peraliphatic nonionic additive ranges from about 0.7 to about 2.5.

Methyl branches may represent between about 20 percent to about 99percent of the total number of branches present in the branched nonionicadditive. In some embodiments, methyl branches may represent greaterthan about 50 percent of the total number of branches in a branchednonionic additive. The number of ethyl branches in the alcohol mayrepresent, in certain embodiments, less than about 30 percent of thetotal number of branches. In other embodiments, the number of ethylbranches, if present, may be between about 0.1 percent and about 2percent of the total number of branches. Branches other than methyl orethyl, if present, may be less than about 10 percent of the total numberof branches. In some embodiments, less than about 0.5 percent of thetotal number of branches are neither ethyl nor methyl groups.

In an embodiment, an aliphatic nonionic additive may be a long chainaliphatic alcohol. The term “long chain,” as used herein, refers to acarbon chain having an average carbon number from 10 to 30. A long chainaliphatic alcohol (e.g., a long chain primary alcohol) may be purchasedcommercially (e.g., NEODOL alcohols manufactured by Shell Chemical Co.,Houston, Tex.). In certain embodiments, a long chain aliphatic alcoholmay be prepared by a variety of generally known methods. A long chainaliphatic alcohol may have an average carbon number from 10 to 24. Insome embodiments, a long chain aliphatic alcohol may have an averagecarbon number from 12 to 18. In other embodiments, a long chainaliphatic alcohol may have an average carbon number from 16 to 17.

In an embodiment, a portion of the long chain aliphatic alcohol may bebranched. Branched long chain aliphatic alcohols may be prepared byhydroformylation of a branched olefin. Preparations of branched olefinsare described in U.S. Pat. No. 5,510,306 to Murray, entitled “Processfor Isomerizing Linear Olefins to Isoolefins;” U.S. Pat. No. 5,648,584to Murray, entitled “Process For Isomerizing Linear Olefins toIsoolefins” and U.S. Pat. No. 5,648,585 to Murray, entitled “Process ForIsomerizing Linear Olefins to Isoolefins,” all of which are incorporatedby reference herein. Preparations of branched long chain aliphaticalcohols are described in U.S. Pat. No. 5,849,960 to Singleton et al.,entitled “Highly Branched Primary Alcohol Compositions, andBiodegradable Detergents Made Therefrom;” U.S. Pat. No. 6,150,222 toSingleton et al., entitled “Highly Branched Primary AlcoholCompositions, and Biodegradable Detergents Made Therefrom;” U.S. Pat.No. 6,222,077 to Singleton et al., entitled “Highly Branched PrimaryAlcohol Compositions, and Biodegradable Detergents Made Therefrom,” allof which are incorporated by reference herein.

In some embodiments, branches of a branched aliphatic group of a longchain aliphatic alcohol may have less than about 0.5 percent aliphaticquaternary carbon atoms. In an embodiment, an average number of branchesper long chain aliphatic alcohol ranges from about 0.1 to about 2.5. Inother embodiments, an average number of branches per alcohol ranges fromabout 0.7 to about 2.5.

Methyl branches may represent between about 20 percent to about 99percent of the total number of branches present in the branched longchain aliphatic alcohol. In some embodiments, methyl branches mayrepresent greater than about 50 percent of the total number of branchesin a branched long chain aliphatic alcohol. The number of ethyl branchesin the alcohol may represent, in certain embodiments, less than about 30percent of the total number of branches. In other embodiments, thenumber of ethyl branches, if present, may be between about 0.1 percentand about 2 percent of the total number of branches. Branches other thanmethyl or ethyl, if present, may be less than about 10 percent of thetotal number of branches. In some embodiments, less than about 0.5percent of the total number of branches are neither ethyl nor methylgroups.

C.4. Aliphatic Anionic Surfactants

In an embodiment, an aliphatic anionic surfactant may be used in ahydrocarbon recovery composition. In certain embodiments, an aliphaticportion of an aliphatic anionic surfactant may have an average carbonnumber from 10 to 24. In some embodiments, an aliphatic portion of analiphatic anionic surfactant may have an average carbon number from 12to 18. In other embodiments, an aliphatic portion of an aliphaticanionic surfactant may have an average carbon number from 16 to 17. Insome embodiments, the aliphatic anionic surfactant may include abranched aliphatic portion. In some embodiments, a branched aliphaticgroup of an aliphatic anionic surfactant may have less than about 0.5percent aliphatic quaternary carbon atoms. In an embodiment, an averagenumber of branches per aliphatic anionic surfactant ranges from about0.1 to about 2.5. In other embodiments, an average number of branchesper aliphatic anionic surfactant ranges from about 0.7 to about 2.5.

Methyl branches may represent between about 20 percent to about 99percent of the total number of branches present in the branched anionicsurfactant. In some embodiments, methyl branches may represent greaterthan about 50 percent of the total number of branches in a branchedanionic surfactant. The number of ethyl branches in the alcohol mayrepresent, in certain embodiments, less than about 30 percent of thetotal number of branches. In other embodiments, the number of ethylbranches, if present, may be between about 0.1 percent and about 2percent of the total number of branches. Branches other than methyl orethyl, if present, may be less than about 10 percent of the total numberof branches. In some embodiments, less than about 0.5 percent of thetotal number of branches are neither ethyl nor methyl groups.

In an embodiment which further employs aliphatic anionic surfactant, asolution may be provided which contains an effective amount of analiphatic anionic surfactant selected from the group of compounds havingthe general formula: R₁O(C₃H₆O)_(m)(C₂H₄O)_(n)YX wherein R₁ is a linearor branched alkyl radical, an alkenyl radical, or an alkyl or alkenylsubstituted benzene radical, the non-aromatic portion of the radicalcontaining from 6 to 24 carbon atoms; m has an average value of from 1to 10; n has an average value of from 1 to 10; Y is a hydrophilic group;and X is a cation, preferably monovalent, for example N, K, NH₄ ⁺. Y isa suitable hydrophilic group or substituted hydrophilic group such as,for example, the sulfate, sulfonate, phosphonate, phosphate orcarboxylate radical. Preferably, R₁ is a branched alkyl radical havingat least two branching groups and Y is a sulfonate or phosphate group.

C.5. Other Optional Additives for Enhanced Oil Recovery

The aqueous fluid of the present invention may, optionally, furthercomprise clay stabilization or sand stabilization material. During oilrecovery processes, sands and other materials may become entrained inthe recovered oil. This may be mitigated by the addition of a claystabilization or sand stabilization material. Suitable claystabilization or sand stabilization materials include epoxy resins,polyfunctional cationic polymers, such aspoly(N-acrylamidomethyltnrnethyl ammonium chloride) orpoly(vinylbenzyltrimethyl ammonium chloride).

Other optional ingredients that may be added to the aqueous fluid of thepresent invention include, but are not limited to polymers such asbiopolysaccharides, cellulose ethers, acrylamide-derived polymers,corrosion inhibitors, oxygen scavengers, bactericides, and so forth, andany combination thereof.

The aqueous fluid of the present invention is introduced into the crudeoil-bearing formation, typically by injecting the fluid into theformation.

In the case of a carbonate formation having hydrophobic surfaces,addition of the organophosphorous material to the aqueous flooding fluidmodifies such surfaces to increase the surface energy of such surfacesand render such surfaces more readily wettable by water. The surfacemodified formation more readily imbibes the aqueous flooding fluid, thusincreasing the amount of aqueous fluid imbibed by the formation andincreasing the amount of crude oil displaced from the formation by theaqueous fluid.

The aqueous fluid may be used in secondary or tertiary oil recoveryprocesses, although the use of such fluids in other applications is alsonot excluded.

C.6. Methods of Use for Enhanced Oil Recovery

The aqueous medium utilized to form the solution including theorganophosphorous material of the invention can be soft water, brackishwater, or a brine. The aqueous fluid of the present invention isintroduced into the crude oil-bearing formation, typically by injectingthe fluid into the formation.

Optionally, after injection of the aqueous fluid comprising the presentphosphate esters of the present invention addition to crude oil havinggenerally the viscosity of the oil-bearing formation of the oil well tobe treated, various hydrocarbon solvents may be employed to displace theaqueous solution out into the reservoir. Such hydrocarbon solvents asthe low molecular weight, generally liquid hydrocarbons boiling belowthe gasoline range, such as the lower alkanes including butane, propane,pentane, hexane and heptane, as well as natural gasoline, petroleumnaphtha and kerosene or mixtures of these hydrocarbons, are useful. Bothsweet and sour crude oil is useful as a hydrocarbon to displace theaqueous solution out into the subterranean reservoir of oil or gas.

Optionally, injection of a preflush fluid may be utilized prior toinjection of the aqueous fluid of the present invention. The preflushmay consist of a hydrocarbon fluid, a brine solution, or simply water.

Also, injection of the aqueous fluid comprising the present phosphateesters may optionally be followed by an injection of a surfactant, amobility control fluid or a polymeric flush, which is typically apolymer-thickened aqueous solution, using, for example the polymersdisclosed above, into the formation to further enhance oil recovery. Thepolymeric solution is utilized to drive or push the now oil bearingsurfactant flood out of the reservoir, thereby “sweeping” crude oil outof the reservoir. Further, the polymeric solution has a very highviscosity which helps to prevent what is referred to in the industry aschanneling or “fingering”, thus improving sweep efficiency.

This polymeric flush or mobility control fluid may once again befollowed by a water flush which may be brine or saline or softenedwater, or fresh water.

Oil is recovered at a production well to be spaced apart from theinjection well as the drive fluid pushes the mobility buffer slug whichsweeps the oil out of the pores in the formation and to the productionwell. Once the water/oil emulsion reaches the surface, it is put intoholding tanks where it is subsequently demulsified, thereby allowing theoil to separate from the water through the natural forces of gravity.

For example, a hydrocarbon recovery composition including the phosphateesters of the present invention may be added to a portion of hydrocarboncontaining formation that may have an average temperature of less than80° C. To facilitate delivery of an amount of the hydrocarbon recoverycomposition to the hydrocarbon containing formation, the hydrocarboncomposition may be combined with water or brine to produce an injectablefluid. Typically about 0.01 to about 5 wt % of the phosphate ester,based on the total weight of injectable fluid, may be injected into thehydrocarbon containing formation through an injection well. In certainembodiments, the concentration of the hydrocarbon recovery compositioninjected through the injection well may be about 0.05% to about 3 wt. %,based on the total weight of injectable fluid. In some embodiments, theconcentration of the hydrocarbon recovery composition may be about 0.1%to about 1 wt. % based on the total weight of injectable fluid.

In some embodiments, a hydrocarbon recovery composition may be added toa portion of a hydrocarbon containing formation.

XI. Home Care or Industrial Care Compositions

In one embodiment, the present invention is directed to a home care orindustrial cleaning composition, such as a liquid detergent, a laundrydetergent, a hard surface cleanser, a dish wash liquid, or a toilet bowlcleaner, comprising water, one or more surfactants, and a polymer of thepresent invention. Suitable surfactants include those described above inregard to the personal care composition embodiments of the presentinvention. Such cleaning compositions may optionally further compriseone or more of water miscible organic solvents, such as alcohols andglycols, and/or one or more additives.

Suitable additives are known in the art and include, for example,organic builders, such as organophosphonates, inorganic builders, suchas ammonium polyphosphates, alkali metal pyrophosphates, zeolites,silicates, alkali metal borates, and alkali metal carbonates, bleachingagents, such as perborates, percarbonates, and hypochlorates,sequestering agents and anti-scale agents, such as citric acid andethylenediaminetetraacetic acid, inorganic acids, such as phosphoricacid and hydrochloric acid, organic acids, such as acetic acid,abrasives, such as silica or calcium carbonate, antibacterial agents ordisinfectants, such as triclosan and cationic biocides, for example(N-alkyl)benzyldimethylammonium chlorides, fungicides, enzymes,opacifing agents, pH modifiers, dyes, fragrances, and preservatives.

In an embodiment the home care or industrial cleaner benefit agent isselected from the group consisting of soil release agents, fabricsoftener, surfactants, builders, binders, bleach and fragrances.

In an embodiment the home care or industrial cleaning composition forcleaning fabrics or hard surfaces comprising, the composition of thepresent invention and a surfactant and a home care or industrial cleanerbenefit agent.

In an embodiment the composition is a detergent composition andcomprises: the polymer, at least one detersive surfactant, and abuilder.

The invention also encompasses a method for cleaning a substrateselected from the group consisting of a hard surface and a fabric,comprising applying the composition of the present invention to thesubstrate.

Examples of the prevent invention are set forth below. Unless otherwiseindicated, all parts, percentages, and proportions herein are by weight.

EXAMPLES

Preparation of mono-[2-(methacryloyloxy)ethyl]phthalate (also known as2-(2-carboxybenzoyloxy)ethyl methacrylate, MAEP)

Example 1 Imidazole as Catalyst

To a 0.5 liter jacketed reactor equipped with mechanical stirrer,condenser and addition funnel was added 2-hydroxyethy methacrylate (100g, 0.77 mol) and 4-methoxyphenol (MEHQ) (0.16 g). The mixture wasstirred with the initiation of 8% Oxygen in Nitrogen sub-surface purge.The mixture was heated to a set point of 80° C. and phthalic anhydride(39 g, 0.26 mol) was added through an addition funnel. Imidazole (1.57g, 0.023 mol) was added to the mixture, resulting in an immediateexotherm. Additional phthalic anhydride (78 g, 0.53 mol) was addedthrough the addition funnel over a 10 min. period. The reaction mixturewas heated at 76° C. for 5 hours, allowed to cool and the MAEP productwas isolated as a clear colorless viscous liquid (210 g). ¹H NMR(CDCl₃), 400 MHz, ppm; 7.89 (1H, d, J=6.2 Hz), 7.69 (1H, d, J=7.1 Hz),7.62-7.55 (2H, m), 6.12 (1H, s), 5.55 (1H, s), 4.58-4.56 (2H, m)4.46-4.44 (2H, m), 1.91 (3H, s). Only residual quantities of2-hydroxyethyl methacrylate and phthalic anhydride were observed in thisisolated product.

Example 2 2,6-Di-Tert-Butyl-4-((Dimethylamino)Methyl)Phenol as Catalyst

To a 0.25 liter 4-neck round bottom flask equipped with mechanicalstirrer, condenser and heating mantel was added 2-hydroxyethymethacrylate (20 g, 0.153 mol). Stirring was initiated along with 8%Oxygen in Nitrogen sub-surface purge.

2,6-di-tert-butyl-4-((dimethylamino)methyl)phenol (1.2 g, 4.6 mmol) wasadded and the mixture was heated to a set point of 80° C. Phthalicanhydride (23.6 g, 0.16 mol) was then added over a ten minute period.The reaction mixture was heated at 82° C. for an additional 5 hours,allowed to cool and the MAEP product was isolated as a clear viscousliquid (41.3 g). ¹H NMR consistent with that of Example 1.

Example 3 2,4,6-Tris((Dimethylamino)Methylphenol as Catalyst

To a 0.25 liter 4-neck round bottom flask equipped with mechanicalstirrer, condenser and heating mantel was added 2-hydroxyethymethacrylate (20 g, 0.153 mol). Stirring was initiated along with 8%Oxygen in Nitrogen sub-surface purge.2,4,6-tris((dimethylamino)methylphenol (0.41 g, 1.5 mmol) was added andthe mixture was heated to a set point of 82° C. Phthalic anhydride (23.6g, 0.16 mol) was then added over a ten minute period. The reactionmixture was heated at 82° C. for an additional 5 hours, allowed to cooland the MAEP product was isolated as a clear viscous liquid (40.5 g). ¹HNMR consistent with that of Example 1.

The following examples evaluate ofmono-[2-(methacryloyloxy)ethyl]phthalate (also known as2-(2-carboxybenzoyloxy)ethyl methacrylate, MAEP) andmono-[2-(Methacryloyloxy)ethyl hexahydro]phthalate (MAHP)

Example 4 Preparation of HASE Systems

The typical polymerization ingredients and amounts used to makeexperimental HASE polymers for evaluation are summarized in TABLE 1.

TABLE 1 Ingredient Active weight ingredient Ingredients Concentration(grams) weight (grams) KETTLE CHARGE Deionized water 100% 160.00 160.00RHODAPEX AB20  29% 1.01 0.29 Ammonium persulfate 100.00%   0.26 0.26MONOMER EMULSION Deionized water 100% 107.22 RHODAPEX AB20  29% 1.010.29 Methyl acrylic acid 29.20 29.20 Ethyl acrylate 81.76 81.76Hydrophobic Monomer 50.00%  11.68 5.84 MAEP or MAHP 82.00%  29.20INITIATOR SOLUTION Deionized water 30.00 30.00 Ammonium persulfate 0.370.37 CHASER SOLUTION Part 1 Terbutyl 0.51 0.51 peroxybenzoate Part 2Isoascorbic acid 0.26 0.26 (araboascorbic acid) Deionized water 8.768.76 Total 461.24 Theoretical Solids 30.1%  Scale-up factor 1.46 Seed  2.0% ME 5.20   25.0% IS 7.59

The HASE polymers are each made according to the following procedure.Add heat to kettle charge to about 80° C. while purging with N₂.Maintain N₂ blanket throughout run. At about 80° C., add 25% Initiatorsolution and 2% Monomer emulsion. Hold at that temperature for about 15minutes. Feed remainder of monomer emulsion and initiator solution over3 hours. Hold for 30 minutes, and add the chaser solution. Finally, heatto about 80° C. and hold for 30 minutes, and allow cooling.

In TABLE 1 RHODAPEX AB20 is a commercially available sulfated alcoholethoxylate surfactant from Rhodia. Ammonium persulfate is an initiator.The initiator and chaser solutions are provided to convert left overmonomers to oligomerize them to reduce VOCs. If desired to avoid theinitiator and chaser solutions excess monomer could be removed bystripping. ME is an abbreviation for monomer emulsion. IS is anabbreviation for initiator solution.

MAEP is mono-[2-(methacryloyloxy)ethyl]phthalate. MAHP ismono-[2-(Methacryloyloxy)ethyl hexahydro]phthalate. These areembodiments of first acidic monomers.

Methyl acrylic acid is an embodiment of a second acidic monomer.

Ethyl acrylate is an embodiment of a nonionic, copolymerizable C2-C12alpha, beta-ethylenically unsaturated monomer.

The hydrophobic monomer of Example 4 is a Nopol alkoxylate according tostructure (VI):

The Nopol alkoxylate is made as follows: Nopol is alkoxylated withpropylene oxide and ethylene oxide charged to a glass flask equippedwith a PTFE blade agitator, temperature sensor, dry compressed air purgeline and a water cooled condenser. The liquid ethoxylate is warmed,stirred, and MEHQ is added. A purge of dry air is passed through theliquid and later methacrylic anhydride is added. The temperature isstabilized and held between 70-74° C. for five and a half hours, andthen the liquid is cooled. Methacrylic acid and water are added and theliquid product is discharged.

TABLE 2A and TABLE 2B show results of latex characterization of HASEpolymers as thickeners synthesized from ingredients generally inaccordance with TABLE 1 such as MAEP or MAHP as a first acidic monomer,methyl acrylic acid as a second acidic monomer, ethyl acrylate as anonionic, copolymerizable C2-C12 alpha, beta-ethylenically unsaturatedmonomer, and a hydrophobic monomer. However, the hydrophobic monomer isHydrophobic Monomer 1 having formula VIa:

In TABLEs 2A and 2B Particle Size is average particle size. PDI ispolydispersity index. ME is an abbreviation for monomer emulsion. %Coagulum is % undesired solids.

TABLE 2A Latex characterization of HASE thickeners synthesized frommethyl acrylic acid, ethyl acrylate, Hydrophobic Monomer 1, and MAEPHASE Z-Average % Solids Polymer Particle Size PDI % Coagulum Content1^(a) 164.2 0.014 0.0698 30.66 2^(b) 123.9 0.019 0.109 31.65 3^(c) 156.10.019 0.202 32.09 4^(d) 173.1 0.012 0.102 31.52 5^(e) 131.9 0.04 0.089133.52 6^(f) 124 0.047 0.161 33.04 7^(g) 137 0.029 0.256 33.98^(a)Polymer synthesized using 1:0 MAEP/MAA ratio ^(b)Polymer synthesizedusing 1:1 MAEP/MAA ratio ^(c)Polymer synthesized using 1:3 MAEP/MAAratio ^(d)Polymer synthesized using 1:9 MAEP/MAA ratio ^(e)Polymersynthesized using 1:1 MAEP/MAA ratio (less initiator added) ^(f)Polymersynthesized using 1:1 MAEP/MAA ratio (more Hydrophobic Monomer 1 added)^(g)Polymer synthesized using 1:1 MAEP/MAA ratio (less initiator andmore Hydrophobic Monomer 1 added)

TABLE 2B Latex characterization of HASE Polymers 8-12 synthesized frommethyl acrylic acid, ethyl acrylate, Hydrophobic Monomer 1, and MAEP orMAHP HASE Z-average % Solids Polymer Particle Size PDI pH % CoagulumContent  8^(h) 161.30 0.024 2.06 0.037 31.87  9^(i) 174.70 0.070 2.110.050 32.63 10^(j) 199.7 0.071 2.60 0.158 31.29 11^(k) 147.30 0.021 2.380.024 30.54 12^(l) 147.6 0.005 2.70 0.010 30.10 ^(h)Polymer synthesizedusing 1:1 MAEP/MAA ratio ^(i)Polymer synthesized using 1:3 MAEP/MAAratio ^(j)Polymer synthesized using 0:1 MAEP/MAA ratio (control)^(k)Polymer synthesized using 1:0 MAEP/MAA ratio ^(l)Polymer synthesizedusing 1:0 MAHP/MAA ratio

Example 5 Sample Preparation for Thickening Efficiency (KU)

Formulation preparation combined 108 grams Binder latex (RHOPLEXSG30)+61 grams Deionized water+HASE polymer as a thickener. The binderlatex RHOPLEX SG30 is an acrylic emulsion available from the DowChemical Company.

TABLES 3A and 3B show thickening efficiency in RHOPLEX SG30.

TABLE 3A lists Examples A-F which employed HASE Polymers 2-7 of TABLE 2Aabove.

TABLE 3B lists Examples G-K which employed HASE Polymers 8-12 of TABLE2B above.

The HASE polymer was added as a thickener until a KU viscosity of 95 +−2 and pH=9-9.3 was reached.

TABLE 3A Thickening Efficiency of HASE Polymer in RHOPLEX SG30 AcrylicEmulsion Binder and KU ICI HASE Polymer HASE Efficiency Visc. Visc. BV(LV 4 System Polymer (g) pH (KU) (P) @ 60 RPM) A 2^(a) 3.55 9.02 93.52.2 3249 B^(b) 3^(b) 3.3 9.174 95.7 1.6 3439 C 4^(c) 3.16 9.462 96.40.50 3339 D 5^(d) 3.14 9.28 94.2 0.80 3759 E 6^(e) 3.78 9.004 95.4 0.63959 F 7^(f) 31.0 9.255 93.2 0.60 4209 ^(a)Polymer synthesized using 3:1MAEP/MAA ratio ^(b)Polymer synthesized using 1:3 MAEP/MAA ratio^(c)Polymer synthesized using 1:9 MAEP/MAA ratio ^(d)Polymer synthesizedusing 1:1 MAEP/MAA ratio (less initiator added) ^(e)Polymer synthesizedusing 1:1 MAEP/MAA ratio ^(f)Polymer synthesized using 1:1 MAEP/MAAratio (less initiator and more Hydrophobic Monomer 1 added)

TABLE 3B Thickening Efficiency of HASE Polymer in RHOPLEX SG30 AcrylicEmulsion Binder and KU ICI BV HASE Polymer HASE Efficiency Visc. Visc.(LV 4 @ System Polymer (g) pH (KU) (P) 60 RPM) G  8^(h) 3.71 9.02 93.20.40 3359 H  9^(i) 3.04 9.05 95.3 0.40 3299 I 10^(j) 2.77 9.25 96.4 0.503339 J 11^(k) 21.47 9.15 94.2 0.80 3759 K 12^(l) 31.0 9.16 93.5 0.604209 ^(h)Polymer synthesized using 1:1 MAEP/MAA ratio ^(i)Polymersynthesized using 1:3 MAEP/MAA ratio ^(j)Polymer synthesized using 0:1MAEP/MAA ratio (control) ^(k)Polymer synthesized using 1:0 MAEP/MAAratio ^(l)Polymer synthesized using 1:0 MAHP/MAA ratio

FIG. 1 shows Viscosity Profiles of Formulations prepared with HASEthickeners containing EGMHPT and MEPHM (in RHOPLEX SG30).

FIG. 2 show Yield Stresses of Formulations prepared with HASE thickenerscontaining MAEP and MAHP (in RHOPLEX SG30).

FIG. 3 shows thixotropic measurement of Binder and HASE Polymer System Kof HASE polymer 12 in RHOPLEX SG30 (couette). In this example:Temperature was 25.0 degrees C. Couette flow refers to the laminar flowof a viscous fluid in the space between a bob and cup, one of which ismoving relative to the other.

FIG. 4 shows the measurement of Binder and HASE Polymer System J of HASEpolymer 11 in RHOPLEX SG30 (couette). In this example Temperature was25.0 degrees C.

The data shows HASE thickeners incorporating MAEP and Methacrylic Acid(MAA) show good thickening efficiency.

It should be apparent embodiments other than those expressly describedabove come within the spirit and scope of the present invention. Thus,the present invention is not defined by the above description but by theclaims appended hereto.

1-13. (canceled)
 14. An aqueous composition, comprising water and a pHresponsive copolymer of unsaturated copolymerizable monomers, saidunsaturated copolymerizable monomers comprising, based on total weightof monomers: A. about 0.1-70 weight percent first acidic monomerselected from at least one member of the group consisting ofmono-[2-(methacryloyloxy)ethyl]phthalate andmono-[2-(Methacryloyloxy)ethyl hexahydro]phthalate, B. about 0-45 weightpercent of at least one C3-C8 alpha beta-ethylenically unsaturatedsecond acidic monomer, preferably a C3-C8 alpha beta-ethylenicallyunsaturated carboxylic acid monomer; C. about 15-70 weight percent of atleast one nonionic, copolymerizable C2-C12 alpha, beta-ethylenicallyunsaturated monomer; and D. about 0 to 30 weight percent of at least onenonionic ethylenically unsaturated hydrophobic monomer.
 15. The aqueouscomposition of claim 14, further comprising an emulsifier, wherein theaqueous composition is a pH responsive composition.
 16. The aqueouscomposition of claim 15, having an average particle size of about 500 toabout 3000 angstroms and a Brookfield viscosity of about 100 to about500,000, cps as a 1 percent aqueous solution in ammonium salt at pH 9.0and 25 degrees C.
 17. The aqueous composition of claim 14, wherein thecomposition comprises, based on 100 parts by weight of the composition,from about 0.05 parts by weight to about 20 parts by weight of the pHresponsive polymer.
 18. The aqueous composition of claim 14, wherein thecomposition is an emulsion comprising an effective amount of the pHresponsive compound, and further comprises an emulsifier and a filmforming polymer latex, wherein the pH responsive copolymer is present inan amount effective for modifying the rheological properties of theemulsion.
 19. The composition of claim 16, further comprising one ormore of a pigment, a filler, or an extender.
 20. The aqueous compositionof claim 18, wherein the emulsion is selected from the group consistingof a latex paint, a latex coating, a cosmetic, a detergent/cleanser, andan oilfield drilling fluid.
 21. The aqueous composition of claim 20,wherein the emulsion is a latex paint, further comprising at least oneadditive selected from the group consisting of dispersants, surfactants,rheology modifiers, defoamers, thickeners, biocides, mildewcides,colorants, waxes, perfumes and co-solvents to a mixture comprising thelatex polymer and water. 22-23. (canceled)
 24. The aqueous compositionof claim 14, wherein the composition is a personal care composition andfurther comprises one or more surfactants.
 25. The aqueous compositionof claim 14, wherein the one or more surfactants comprise at least oneanionic surfactant and the composition further comprises a structuringagent for the anionic surfactant.
 26. The aqueous composition of claim14, further comprising a personal care benefit agent.
 27. The aqueouscomposition of claim 14, wherein the composition is a particledispersion and further comprises particles dispersed in the composition.28. A method for handling particles, comprising dispersing the particlesin a composition according to claim 27, to form an aqueous particledispersion.
 29. The method of claim 28, further comprising transportingthe aqueous particle dispersion by pumping the aqueous particledispersion through a conduit.
 30. The method of claim 29, comprisingdirecting a stream of the composition into a subterranean formation,wherein the composition is a hydraulic fracturing composition andfurther comprises a proppant.
 31. The aqueous composition of claim 14,wherein the composition is a hydraulic fracturing composition andfurther comprises a proppant.
 32. A method for fracturing a geologicformation, comprising directing a stream of the composition of claim 31at a surface of the formation at a pressure and flow rate at leastsufficient to initiate, extend, or initiate and extend one or morefractures in the formation.
 33. A method for thickening an aqueousemulsion, comprising: forming a blend by blending with the aqueousemulsion an amount of the pH-responsive composition of claim 12effective to thicken the aqueous emulsion when pH of the blend isadjusted to a pH in the range of about 6.5 to about
 11. 34. A processcomprising the steps of: mixing 100 parts by weight 2-hydroxyethymethacrylate (HEMA) and 0.1 to 0.5 parts by weight 4-methoxyphenol(MEHQ) to form a mixture; heating the mixture to a set point of 70-100°C. with NOx sparge and then adding 25-50 parts by weight phthalicanhydride as a first dose of phthalic anhydride to the heated mixture;after adding the first dose of phthalic anhydride then adding 1-3 partsby weight imidazole to the mixture; after adding the imidazole thenadding 50 to 90 parts by weight phthalic anhydride as a second dose ofphthalic anhydride; after adding the second dose of phthalic anhydridethen heating the reaction mixture at 70-90° C. to formmono-[2-(methacryloyloxy)ethyl]phthalate; and recovering themono-[2-(methacryloyloxy)ethyl]phthalate.
 35. A process comprising thesteps of: mixing 15-25 parts by weight 2-hydroxyethy methacrylate (HEMA)and at least one member of the group consisting of 1-3 parts by weight2,6-di-tert-butyl-4-((dimethylamino)methyl)phenol or 0.2-2 parts byweight 2,4,6-tris((dimethylamino)methyl)phenol; heating the mixture to aset point of 70-100° C. with NOx sparge and then adding 10-30 parts byweight phthalic anhydride to the heated mixture; after adding thephthalic anhydride then heating the reaction mixture at 70-90° C. toform mono-[2-(methacryloyloxy)ethyl]phthalate; and recovering themono-[2-(methacryloyloxy)ethyl]phthalate.
 36. The process of claim 35wherein the process is performed with an absence of MEHQ and an absenceof base catalyst.
 37. The process of claim 35 wherein the process isperformed with an absence of base catalyst.
 38. A method for promotingpersonal care comprising applying the copolymer of claim 1 to skin orhair of a user.
 39. A home care or industrial cleaning composition forcleaning fabrics or hard surfaces comprising, the copolymer of claim 1and a surfactant and a home care or industrial cleaner benefit agent.40. A method for cleaning a substrate selected from the group consistingof a hard surface and a fabric, comprising applying the composition ofclaim 39 to the substrate.